Reaction Rate amp Equilibrium

Collision Theory

bull When one substance is mixed with another the two substances do not react on a macroscopic basis but react as their individual particles (atoms molecules or ions) come together

bull The factors that affect how these particles come together are the factors that influence the rate of a reaction

bull In order for the reaction to occur the particles involved must collide with each other the more often the particles collide the faster the reaction occurs

bull Not every collision results in a reaction

NO3(g) + CO(g) NO2(g) + CO2(g)

bull The colliding molecules must have enough energy to react and form an activated complex

bull This minimum amount of energy is called the activation energy

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Collision Theory

bull When one substance is mixed with another the two substances do not react on a macroscopic basis but react as their individual particles (atoms molecules or ions) come together

bull The factors that affect how these particles come together are the factors that influence the rate of a reaction

bull In order for the reaction to occur the particles involved must collide with each other the more often the particles collide the faster the reaction occurs

bull Not every collision results in a reaction

NO3(g) + CO(g) NO2(g) + CO2(g)

bull The colliding molecules must have enough energy to react and form an activated complex

bull This minimum amount of energy is called the activation energy

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull The factors that affect how these particles come together are the factors that influence the rate of a reaction

bull In order for the reaction to occur the particles involved must collide with each other the more often the particles collide the faster the reaction occurs

bull Not every collision results in a reaction

NO3(g) + CO(g) NO2(g) + CO2(g)

bull The colliding molecules must have enough energy to react and form an activated complex

bull This minimum amount of energy is called the activation energy

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull In order for the reaction to occur the particles involved must collide with each other the more often the particles collide the faster the reaction occurs

bull Not every collision results in a reaction

NO3(g) + CO(g) NO2(g) + CO2(g)

bull The colliding molecules must have enough energy to react and form an activated complex

bull This minimum amount of energy is called the activation energy

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull Not every collision results in a reaction

NO3(g) + CO(g) NO2(g) + CO2(g)

bull The colliding molecules must have enough energy to react and form an activated complex

bull This minimum amount of energy is called the activation energy

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

NO3(g) + CO(g) NO2(g) + CO2(g)

bull The colliding molecules must have enough energy to react and form an activated complex

bull This minimum amount of energy is called the activation energy

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull The colliding molecules must have enough energy to react and form an activated complex

bull This minimum amount of energy is called the activation energy

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull This minimum amount of energy is called the activation energy

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull The activated complex is the temporary arrangement of atoms as they change from reactants into products

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Reaction Ratebull Is affected by the following

bull Temperaturebull Concentration of reactantsbull Particle SizeSurface Areabull Catalystsbull Nature of the Reactant

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Effect of Temperature on Reaction Rate

bull Increasing the temperature increases the rate of a reaction

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull At higher temperatures the particles have more energy move faster and collide more frequently

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull More importantly the higher energy of the particles means that

bull more of the particles have sufficient energy (activation energy)

bull to have a successful collision (form an activated complex)

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull In an exothermic reaction the addition of a small amount of heat can often have a dramatic effect on the rate of reaction

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull This small addition of energy gives a few particles the activation energy they react and release more energy which is absorbed by more particles which react and release more energy hellip

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Effect of Concentration on Reaction Rate

bull Increasing the concentration of the reactants increases the rate of a reaction

bull When there are more particles per unit volume they will collide more frequently causing the rate to increase

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Effect of Particle SizeSurface Area

bull Decreasing particle sizeincreasing surface area increases the rate of a reaction

bull When the surface area is increases there is more contact between the reactants the number of collisions increase and therefore the rate of reaction also increases

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Effect of Catalysts bull A catalyst is a substance that increases

the rate of a chemical reaction without being permanently consumed by the reaction

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull A catalyst provides a different pathway or mechanism for the reaction that has a lower activation energy

bull When the activation energy is lower more of the particles will have sufficient energy to react more of the collisions are successful therefore the reaction rate increases

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

A catalyst increases the rate of a reaction by lowering the activation energy

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull Effect of the Nature of the Reactant

bull The nature of the reactants involved will determine the kind of reaction that occurs

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull Reactions with bond rearrangements or electron transfer take longer than reactions without these changes

bull Ionic reactions (such as double displacement or neutralization) occur almost instantly

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull In reactions with acids stronger acids (H2SO4 HNO3 HClO4 HCl HF and HI) will occur faster than reactions with weak acids (all other acids)

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull In reactions with metals more active metals (see activity series) will react faster than less active metals

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Reaction Mechanism

bull Most reactions occur in a series of steps Each step normally involves the collision of only two particles

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull There is little chance of three or more particles colliding with the proper position and sufficient energy to cause a reaction

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull If a reaction consists of several steps such as the following

bull A hellip B bull B hellip C bull C hellip final product

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull One of the steps will be slower than all the others This step is called the rate determining step

bull The other faster steps will not affect the rate of the reaction

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull The series of steps that must occur for a reaction to go to completion is called the reaction mechanism

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

CATALYSIS

bull middot A Catalyst is a substance that speeds up a reaction without being consumed

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull In theory the catalyst may be used over and over again

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull In practice however there is some loss of catalyst through other reactions that occur at the same time (side reactions)

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Importance of Catalysts

bull middot Catalysts allow reactions to occur much faster

bull middot Catalysts allow reactions to occur at lower temperatures (energy savings)

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Characteristics of Catalysts

bull Catalysts are often quite specific They increase the rate of some reactions but not others

bull Enzymes (catalysts used in biological organisms) are extremely selective

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

How Catalysts Work

bull A catalyst is an active participant in the reaction

bull A catalyst must participate in one step of a reaction and be regenerated in a later step

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull The catalyzed reaction mechanism makes available a reaction path having an increased

bull overall rate of reaction by - increasing the frequency factor or - decreasing the Activation Energy Ea

(most dramatic effect)

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

ExampleThe commercial preparation of sulfuric

acid H2SO4 from SO2 NO catalyst

First step 2 SO2 g) + O2(g) 2 SO3(g)

Proposed Mechanismbull 2NO + O2 2 NO2bull NO2 + SO2 NO + SO3 (must occur twice each time the first step

occurs once)

bull catalystbull 2NO + O2 2NO2 reaction intermediate

bull 2NO2 + 2SO2 2NO + 2SO3 ___________________________________

Overall 2 SO2 + O2 2SO3

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Equilibrium Systems

bull In some chemical reactions all of the reactants are converted to products

2Cu(s) + O2(g) 2CuO(s)

This reaction is said to go to completion

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull In other processes however the final mixture consists of both products and reactants

Reactants Products Reactants Products Reactants ProductsThis reaction is at equilibrium

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

The reactants are colliding to form products while the products are also colliding to reform reactants

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull This is known as a dynamic equilibrium ndash the rate of the forward reaction is equal to the rate of the reverse reaction

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull Equilibrium is reached in a closed system when all properties of the system are constant

bull The forward and reverse reactions are happening at the same rate

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

The concentrations of products and reactants may be different but they are no longer changing

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Le Chacirctelierrsquos Principle

bull If a stress is applied to a system at equilibrium the equilibrium will shift to relieve the stress

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull Concentration ndash Increase [reactant] = shifts to use up the

added reactants and produce more products bull 1048766 Shifts right

ndash Increase [product] = shifts to use up added product and product more reactants

bull 1048766 Shifts left ndash Decrease [reactant] = shifts to produce more

reactants bull 1048766 Shifts left

ndash Decrease [product] = shifts to produce more products

bull 1048766 Shifts right

bull bull bull bull bull

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull Temperature ndash Increase = favours the endothermic direction

bull 1048766 The reaction shifts in the direction that uses up the added energy

ndash Decreasing = favours the exothermic direction

bull 1048766 The reaction shifts in the direction that produces energy

bull bull bull

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

bull PressureVolume ndash Increasing pressureDecreasing volume

favours fewer gas molecules bull 1048766 The reaction shifts to relieve the pressure

ndash Decreasing pressureIncreasing volume favours more gas molecules

bull 1048766 The reaction shifts to restore the pressure

bull bull bull

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da

Ta Da

• Reaction Rate amp Equilibrium
• Collision Theory
• Slide 3
• Slide 4
• Slide 5
• NO3(g) + CO(g) NO2(g) + CO2(g)
• Slide 7
• Slide 8
• Slide 9
• Slide 10
• Reaction Rate
• Slide 12
• Slide 13
• Slide 14
• Slide 15
• Slide 16
• Slide 17
• Slide 18
• Slide 19
• Slide 20
• Slide 21
• Slide 22
• Slide 23
• Slide 24
• Slide 25
• Reaction Mechanism
• Slide 27
• Slide 28
• Slide 29
• Slide 30
• CATALYSIS
• Slide 32
• Slide 33
• Importance of Catalysts
• Characteristics of Catalysts
• How Catalysts Work
• Slide 37
• Slide 38
• Example The commercial preparation of sulfuric acid H2SO4 from SO2
• Equilibrium Systems
• Slide 41
• Slide 42
• Slide 43
• Slide 44
• Slide 45
• Le Chacirctelierrsquos Principle
• Slide 47
• Slide 48
• Slide 49
• Ta Da