do-now: “17.4 hess’s law notes write down today’s flt … · take out your calculator,...
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Chemistry Monday, May 7th – Tuesday, May 8th, 2018
Do-Now: “Ch. 10/16 Test Day Do-Now” 1. Write down today’s FLT 2. Tell me two differences between
“endothermic” and “exothermic” reactions/values.
3. What are our three types of heat transfer?
4. What are indicators? 5. Use a pro-talk sentence frame to tell me
about ΔG. 6. Take out your ToC and planner J
Test • Youmayhaveoutyourstampedvocabularychartand/orunitreviewpacket
• Noiselevel0• Eyesonyourownpaper• Checkyouranswers• Flipoverwhendone
CW • Vocabchart
Chemistry Wednesday, May 9th – Thursday, May 10th,
2018
Do-Now: “Video Notes: Kinetics” 1. Write down today’s FLT 2. How did you feel about our last unit test? 3. How does ΔH differ between exothermic and
endothermic reactions? 4. What does it mean if ΔG < 0? 5. What does “molarity” refer to? 6. Bob is performing a chemical reaction in a
lab, but his reaction is going very slowly. What do you think Bob could do to speed up the reaction? Make an educated guess if necessary.
7. Take out your ToC and planner J
Video Notes • Before we start our new notes, we will
watch a video overviewing the concept of chemical kinetics
• During the video, write down five facts that you learn about kinetics
• Focus on new information
FLT • I will be able to identify four factors that
influence the rate of a chemical reaction by completing Ch. 17 Notes Part A
Standard HS-PS1-5:Applyscientificprinciplesandevidencetoprovideanexplanationabouttheeffectsofchangingthetemperatureorconcentrationofthereactingparticlesontherateatwhichareactionoccurs
Ch. 17 A: Rates of Reaction
Recall
Recall • Thermodynamics: • The study of energy changes that
accompany chemical and physical processes
Recall • If we are discussing thermodynamically
favorability, what should we be considering? • Do any of these factors give us information
about the rate of a reaction?
Doallreactionsoccuratthesamerate?
ReactionRates• ChemicalKinetics=Thestudyofthespeedwithwhichreactantsareconvertedtoproducts
ReactionRates• ReactionRate=Thechangeinconc’ofareactantorproductperunitoftime
Aretherefactorsthataffecttherateofthereaction?
Collision Theory
Collision Theory • When suitable particles of the reactant hit each
other, only a certain % of the collisions cause any noticeable or significant chemical change
Collision Theory • Collision Theory (to successfully create
products): ① Molecules must collide with sufficient
activation energy ② Molecules must collide in the correct
orientation • Only successful collisions will lead to chemical
changes (breaking preexisting bonds and forming all new bonds)
• This results in the products of the reaction
Collision Theory
Collision Theory
Energy Diagrams
Energy Diagrams • Recall: we can diagram a reaction’s energy vs.
progress
Energy Diagrams • Activation Energy (Ea) = the minimum E
required for molecules to react • Ea is the difference in energy from the reactants
to the peak of the energy diagram
Energy Diagrams • The greater the Ea, the slower the reaction.
Energy Diagrams • The peak represents a high energy transition
state (called the activated complex ). Bonds are breaking/forming before the final products are made.
Collision Theory
Factors That Affect Rxn Rate
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Factors That Affect Rxn Rate 1. Temperature 2. Surface Area 3. Concentration 4. Presence of a Catalyst
Factors That Affect Rxn Rate 1. Temperature • Higher T = Higher rxn rate • Increasing the T increases the avg. KE of
molecules. • Faster molecules = more collisions • Higher E collisions = more successful collisions
Factors That Affect Rxn Rate • This means it’s more likely that bonds will be
broken and new bonds will form. • An increase in T produces more successful
collisions that are able to overcome the needed activation energy, therefore, a general increase in rxn rate with increasing T
Factors That Affect Rxn Rate 2. Surface Area • Greater SA = Greater rxn rate • The amount of “exposed surface” will directly
affect speed
Surface Area of Reactants
Factors That Affect Rxn Rate 3. Concentration • Higher Conc’ of reactants = Higher rxn rate
(usually) • The more molecules present, the more collisions
occur, the faster the reaction proceeds, the greater the rate.
Factors That Affect Rxn Rate 4. Presence of a Catalyst • Catalysts = substances that speed up rxns • Catalysts are not consumed in chemical rxns,
and can be reused
Factors That Affect Rxn Rate • Most catalysts work by lowering the Ea
needed for the rxn to proceed – therefore, collisions are more successful and the rate increases
• We can see this in a rxn pathway
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Pair-Share-Respond 1. Definetheterm“reactionrate”2. Whatarefourfactorsthataffectrxn
rate?3. Explainhowtemperatureaffectsthe
reactionrate.Bespecific.4. Notallreactantsformproducts.What
doescollisiontheorytellusaboutwhichreactantsareabletoformproducts?
5. Defineactivationenergyandhowcatalystscanaffectit.
Chemistry Friday, May 11th – Monday, May 14th, 2018
Do-Now: “Video Notes: Equilibrium” 1. Writedowntoday’sFLT.2. Whatarefourfactorsthatcanaffectthereaction
rate?3. Twomoleculescollidewithsufficientactivation
energy;however,theydonotformproducts.Whymightthisbe?
4. DrawanenergydiagramforanENDOTHERMICreaction.LabeltheΔH,reactants,products,activationenergy,andtransitionstate.
5. Addalineinadifferentcolortorepresenttheeffectonyourenergydiagramwhenacatalystisadded.
6. TakeoutyourToCandplannerJ
Video Notes • We will now watch a video overviewing
the concept of chemical equilibrium • During the video, write down five facts that
you learn about equilibrium • Focus on:
– What is equilibrium? – What is reversibility? – What does this look like graphically? – Do reactions “end”, and how do you know?
FLT • I will be able to model the concept of
chemical equilibrium by completing Dueling Cylinders Mini-Lab
Standard HS-PS1-6:Refinethedesignofachemicalsystembyspecifyingachangeinconditionsthatwouldproduceincreasedamountsofproductsatequilibrium
Dueling Cylinders • We will complete a mini-lab to investigate
the concept of equilibrium
What’s in a line graph?
DataTable1Time (independent)
Number of people in hallway (dependent)
0 min 32 2 min 29 4 min 17 6 min 3
Graph 1
The effect of _________on__________
Skill2—Interpretlinegraphsandcreatea
claim
With the person sitting next to you, make a claim based on the data displayed in graph. Your claim must be based on evidence.