17.2 measuring and expressing enthalpy changes 1 > copyright © pearson education, inc., or its...

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172 Measuring and Expressing 172 Measuring and Expressing Enthalpy Changes Enthalpy Changes

1

gtgt

Chapter 17Thermochemistry

171 The Flow of Energy

172 Measuring and Expressing Enthalpy Changes

173 Heat in Changes of State174 Calculating Heats of Reaction



2

gtgt

How can you measure the amount of heat released when a match burns

CHEMISTRY amp YOUCHEMISTRY amp YOU

Remember The concept of specific heat allows you to measure heat flow in chemical and physical processes



3

gtgt CalorimetryCalorimetry

Calorimetry

How can you measure the change in enthalpy of a reaction



4


Calorimetry is the measurement of the heat flow into or out of a system for chemical and physical processes



5

gtgt

Calorimetry is the measurement of the heat flow into or out of a system for chemical and physical processesbull In a calorimetry experiment involving an

endothermic process the heat absorbed by the system is equal to the heat released by its surroundings

bull In an exothermic process the heat released by the system is equal to the heat absorbed by its surroundings

CalorimetryCalorimetry



6

gtgt

Calorimetry is the measurement of the heat flow into or out of a system for chemical and physical processesbull The insulated device used to measure the

absorption or release of heat in chemical or physical processes is called a calorimeter




7

gtgt

Constant-Pressure Calorimeters

Foam cups can be used as simple calorimeters because they do not let much heat in or out

bull Most chemical reactions and physical changes carried out in the laboratory are open to the atmosphere and thus occur at constant pressure




8

gtgt


The enthalpy (H) of a system accounts for the heat flow of the system at constant pressure

bull The heat absorbed or released by a reaction at constant pressure is the same as the change in enthalpy symbolized as ΔH




9

gtgt


The value of ΔH of a reaction can be determined by measuring the heat flow of the reaction at constant pressure

bull In this textbook the terms heat and enthalpy change are used interchangeably

bull In other words q = ΔH




10

gtgt


bull To measure the enthalpy change for a reaction in aqueous solution in a foam cup calorimeter dissolve the reacting chemicals (the system) in known volumes of water (the surroundings)




11

gtgt


bull Measure the initial temperature of each solution and mix the solutions in the foam cup

bull After the reaction is complete measure the final temperature of the mixed solutions




12

gtgt


You can calculate the heat absorbed or released by the surroundings (qsurr) using the formula for the specific heat the initial and final temperatures and the heat capacity of water

qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT

bull m is the mass of the water

bull C is the specific heat of water

bull ΔT = Tf ndash Ti




14

gtgt


The heat absorbed by the surroundings is equal to but has the opposite sign of the heat released by the system

qsurr = ndashqsys




15

gtgt


The enthalpy change for the reaction (ΔH) can be written as follows

qsys = ΔH = ndashqsurr = ndashm C ΔT

bull The sign of ΔH is positive for an endothermic reaction and negative for an exothermic reaction




16

gtgt

Constant-Volume Calorimeters

Calorimetry experiments can also be performed at a constant volume using a device called a bomb calorimeter




17

gtgt

Constant-Volume CalorimetersIn a bomb calorimeter a sample of a compound is burned in a constant-volume chamber in the presence of oxygen at high pressure




18


Constant-Volume Calorimetersbull The heat that is

released warms the water surrounding the chamber

bull By measuring the temperature increase of the water it is possible to calculate the quantity of heat released during the combustion reaction



19

gtgt

What type of calorimeter would you use to measure the heat released when a match burns Describe the experiment and how you would calculate the heat released




20

gtgt



A constant-volume or bomb calorimeter would be used to measure the heat released when a match burns The match would be ignited in the chamber By measuring the temperature increase in the water and using the equation q = ndashm C ΔT the heat released q can be calculated



21

gtgt

When 250 mL of water containing 0025 mol HCl at 250degC is added to 250 mL of water containing 0025 mol NaOH at 250degC in a foam-cup calorimeter a reaction occurs Calculate the enthalpy change (in kJ) during this reaction if the highest temperature observed is 320degC Assume that the densities of the solutions are 100 gmL and the volume of the final solution is equal to the sum of the volumes of the reacting solutions

Sample Problem 173Sample Problem 173

Enthalpy Change in a Calorimetry Experiment



22

gtgt

Analyze List the knowns and the unknown1

bull Use dimensional analysis to determine the mass of the water

bull You must also calculate ΔT

bull Use ΔH = ndashqsurr = ndashm C ΔT to solve for ΔH




23

gtgt


KNOWNS UNKNOWN

Cwater = 418 J(gdegC)

Vfinal = VHCl + VNaOH

= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC

densitysolution = 100 gmL

ΔH = kJ




24

gtgt

First calculate the total mass of the water

Calculate Solve for the unknown2

mwater = 500 mL = 500 g1 mL

100 g

Assume that the densities of the solutions are 100 gmL to find the total mass of the water




25

gtgt

Now calculate ΔT


ΔT = Tf ndash Ti = 320degC ndash 250degC = 70degC




26

gtgt

Use the values for mwater Cwater and ΔT to calculate ΔH


Use the relationship 1 kJ = 1000 J to convert your answer from J to kJ


ΔH = ndashqsurr = ndashmwater Cwater ΔT

= ndash(500 g)(418 J(goC))(70degC)

= ndash1500 J = ndash15 kJ



27

gtgt

bull The temperature of the solution increases which means that the reaction is exothermic and thus the sign of ΔH should be negative

bull About 4 J of heat raises the temperature of 1 g of water 1degC so 200 J of heat is required to raise 50 g of water 1degC Raising the temperature of 50 g of water 7degC requires about 1400 J or 14 kJ

bull This estimated answer is very close to the calculated value of ΔH

Evaluate Does the result make sense3




28

gtgt

The initial temperature of the water in a constant-pressure calorimeter is 24degC A reaction takes place in the calorimeter and the temperature rises to 87degC The calorimeter contains 367 g of water which has a specific heat of 418 J(gdegC) Calculate the enthalpy change during this reaction



29

gtgt

ΔH = ndashm C ΔT

= ndash367 g 418 J(gdegC) (87degC ndash 24degC)





30

gtgtThermochemical Thermochemical EquationsEquations

Thermochemical Equations

How can you express the enthalpy change for a reaction in a chemical equation



31


In a chemical equation the enthalpy change for the reaction can be written as either a reactant or a product



32


In the equation describing the exothermic reaction of calcium oxide and water the enthalpy change can be considered a product

CaO(s) + H2O(l) rarr Ca(OH)2(s) + 652 kJ

Calcium oxide is one of the components of cement



33



A chemical equation that includes the enthalpy change is called a thermochemical equation



34


The heat of reaction is the enthalpy change for the chemical equation exactly as it is writtenbull Heats of reaction are reported as ΔH

bull The physical state of the reactants and products must also be given

bull The standard conditions are that the reaction is carried out at 1013 kPa (1 atm) and 25degC

Heats of Reaction



35


CaO(s) + H2O(l) rarr Ca(OH)2(s)

Each mole of calcium oxide and water that reacts to form calcium hydroxide produces 652 kJ of heat

ΔH = ndash652 kJ

bull In exothermic processes the chemical potential energy of the reactants is higher than the chemical potential energy of the products

Heats of Reaction



36


2NaHCO3(s) + 85 kJ rarr Na2CO3(s) + H2O(l) + CO2(g)

Baking soda (sodium bicarbonate) decomposes when it is heated This process is endothermic

Heats of Reaction

The carbon dioxide released in the reaction causes muffins to rise while baking



37



Heats of Reaction

Remember that ΔH is positive for endothermic reactions Therefore you can write the reaction as follows

2NaHCO3(s) rarr Na2CO3(s) + H2O(l) + CO2(g) ΔH = 85 kJ



38


The amount of heat released or absorbed during a reaction depends on the number of moles of the reactant involved

bull The decomposition of 2 mol of sodium bicarbonate requires 85 kJ of heat

bull Therefore the decomposition of 4 mol of the same substance would require twice as much heat or 170 kJ

Heats of Reaction



39


Heats of ReactionTo see why the physical state of the reactants and products must be stated compare the following two equations

difference = 440 kJ

H2O(l) rarr H2(g) + O2(g) ΔH = 2858 kJ 1 2

H2O(g) rarr H2(g) + O2(g) ΔH = 2418 kJ 1 2



40



bull The vaporization of 1 mol of liquid water to water vapor at 25degC requires 440 kJ of heat

H2O(l) rarr H2O(g) ΔH = 440 kJ

difference = 440 kJ





41

gtgt

Calculate the amount of heat (in kJ) required to decompose 224 mol NaHCO3(s)

Using the Heat of Reaction to Calculate Enthalpy Change

2NaHCO3(s) + 85 kJ rarr Na2CO3(s) + H2O(l) CO2(g)




42

gtgt


KNOWNS

UNKNOWN

amount of NaHCO3(s) that decomposes = 224 mol

ΔH = 85 kJ for 2 mol NaHCO3

ΔH = kJ for 224 mol NaHCO3

Use the thermochemical equation to write a conversion factor relating kJ of heat and moles of NaHCO3 Then use the conversion factor to determine ΔH for 224 mol NaHCO3




43

gtgt

Write the conversion factor relating kJ of heat and moles of NaHCO3


The thermochemical equation indicates that 85 kJ are needed to decompose 2 mol NaHCO3(s)

85 kJ2 mol NaHCO3(s)




44

gtgt

Using dimensional analysis solve for ΔH



85 kJ2 mol NaHCO3(s)ΔH = 224 mol NaHCO3(s)

= 95 kJ



45

gtgt

bull The 85 kJ in the thermochemical equation refers to the decomposition of 2 mol NaHCO3(s)

bull Therefore the decomposition of 224 mol should absorb more heat than 85 kJ

bull The answer of 95 kJ is consistent with this estimate





46


Heats of CombustionThe heat of combustion is the heat of reaction for the complete burning of one mole of a substance



47


Heats of CombustionSmall amounts of natural gas within crude oil are burned off at oil refineries

bull This is an exothermic reaction

bull Burning 1 mol of methane releases 890 kJ of heat

bull The heat of combustion (ΔH) for this reaction is ndash890 kJ per mole of methane burned

CH4(g) + 2O2(g) rarr CO2(g) + 2H2O(l) + 890 kJ



48

gtgt

Like other heats of reaction heats of combustion are reported as the enthalpy changes when the reactions are carried out at 1013 kPa and 25degC

Interpret DataInterpret Data

Heats of Combustion at 25degC

Substance Formula ΔH (kJmol)

Hydrogen H2(g) ndash286

CarbonC(s graphite)

ndash394

Methane CH4(g) ndash890

Acetylene C2H2(g) ndash1300

Ethanol C2H6O(l) ndash1368

Propane C3H8(g) ndash2220

Glucose C6H12O6(s) ndash2808

Octane C8H18(l) ndash5471

Sucrose C12H22O11(s) ndash5645



49

gtgt

Which of the following thermochemical equations represents an endothermic reaction

A Cgraphite(s) + 2 kJ Cdiamond(s)

B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51

gtgtKey Concepts amp Key Key Concepts amp Key EquationEquation

The value of ΔH of a reaction can be determined by measuring the heat flow of the reaction at a constant pressure

In a chemical equation the enthalpy change for the reaction can be written as either a reaction or a product




52

gtgt Glossary TermsGlossary Terms

bull calorimetry the precise measurement of heat flow out of a system for chemical and physical processes

bull calorimeter an insulated device used to measure the absorption or release of heat in chemical or physical processes

bull enthalpy (H) the heat content of a system at constant pressure



53


bull thermochemical equation a chemical equation that includes the enthalpy change

bull heat of reaction the enthalpy change for a chemical equation exactly as it is written

bull heat of combustion the heat of reaction for the complete burning of one mole of a substance



54

gtgt

The heat of reaction or process can be determined experimentally through calorimetry

BIG IDEABIG IDEA

Matter and Energy



55

gtgt

END OF 172END OF 172



2

gtgt

How can you measure the amount of heat released when a match burns


Remember The concept of specific heat allows you to measure heat flow in chemical and physical processes



3


Calorimetry




4





5

gtgt







6

gtgt






7

gtgt







8

gtgt







9

gtgt








10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




3


Calorimetry




4





5

gtgt







6

gtgt






7

gtgt







8

gtgt







9

gtgt








10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




4





5

gtgt







6

gtgt






7

gtgt







8

gtgt







9

gtgt








10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




5

gtgt







6

gtgt






7

gtgt







8

gtgt







9

gtgt








10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




6

gtgt






7

gtgt







8

gtgt







9

gtgt








10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




7

gtgt







8

gtgt







9

gtgt








10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




8

gtgt







9

gtgt








10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




9

gtgt








10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




10

gtgt






11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




11

gtgt







12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




12

gtgt



qsurr = m C ΔT




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




13

gtgt


qsurr = m C ΔT







14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




14

gtgt



qsurr = ndashqsys




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




15

gtgt








16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




16

gtgt






17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




17

gtgt





18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




18







19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




19

gtgt





20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




20

gtgt






21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




21

gtgt






22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




22

gtgt








23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




23

gtgt


KNOWNS UNKNOWN



= 250 mL + 250 mL = 500 mL

Ti = 250degC

Tf = 320degC


ΔH = kJ




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




24

gtgt




100 g





25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




25

gtgt

Now calculate ΔT






26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




26

gtgt










27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




27

gtgt








28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




28

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




29

gtgt

ΔH = ndashm C ΔT






30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




30






31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




31





32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




32







33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




33






34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




34





Heats of Reaction



35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




35




ΔH = ndash652 kJ


Heats of Reaction



36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




36




Heats of Reaction




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




37



Heats of Reaction





38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




38





Heats of Reaction



39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




39



difference = 440 kJ





40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




40





difference = 440 kJ





41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




41

gtgt







42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




42

gtgt


KNOWNS

UNKNOWN








43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




43

gtgt








44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




44

gtgt





= 95 kJ



45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




45

gtgt








46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




46





47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




47









48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




48

gtgt






CarbonC(s graphite)

ndash394










49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




49

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




50

gtgt



B 2H2(g) + O2(g) 2H2O + 4836 kJ



51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




51







52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




52







53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




53







54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




54

gtgt


BIG IDEABIG IDEA

Matter and Energy



55

gtgt




55

gtgt


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