1. Chemical Kinetics – study of the rates of chemical reactions
Some reactions we would like to speed up
Some reactions we would like to slow down

2. What are 4 ways to change the rate of a chemical reaction?
Link #1 Link #2 Link #3 Link #4

3. How can we change the rate of chemical reactions?
Change Concentration (or pressure of gases) Change Surface area of a solid video link
Change Temperature Add a catalyst

4. Increasing Concentration Increases # of Collisions
Link to Collision Theory Animation II

5. For each pair of pictures which reaction will be faster and why?
Increasing surface area of solids increases reaction rate by increasing number of collsions

6. Which set of conditions high pressure or low pressure will produce a faster reaction between gases and why?
INCREASING PRESSURE OF GASES INCREASES THE REACTION RATE BY INCREASING THE NUMBER OF COLLISIONS

7. Reactions need a minimum energy (activation energy, Ea) to occur
Link to collision theory animation

8. Height of Ea determines rxn rate; smaller ea = more molecules that have enough energy to overcome ea = faster rxn

9. Impact of temperature on Reaction Rate
↑ Temp → ↑ ave speed → ↑ Energy of collisions % of molecules with Energy ≥ Ea increases at higher T
Link to Phet Simulation

10. Catalysts accelerate reactions without being consumed by lowering the energy of activation
Lower Ea = Faster rxn
Enzyme link

11. Reaction requires collisions in the correct orientation
The two specific atoms in the different molecules that are reacting have to collide
Link to animation

12. Collision theory- atomic level explanation of reaction rates
Requirements for a chemical Reaction:
Collision between reacting molecules
# of collisions can be increased by :
i) Increasing concentration
ii) Increasing surface area for solid reactants
2) Collision must have sufficient Energy
Energy of collisions impacted by:
i) Temperature,
↑ Temp → ↑ ave speed → ↑ Energy of collisions
ii) Catalyst – speeds up reaction without being consumed by lowering energy of activation
3) Collisions must have correct orientation

13. Summary OF Collision Theory

14. Link to Phet Simulation Link to Collision Theory Animation II

15. Link to reaction profile diagram animation Link to collision theory animation

16. Chem Demos II – Chapter 22 – Iodine Clock (concentration and temperature) Chem Demos II Chapter 20 – Catalyst Surface Area- Demo with alka seltzer tablets Chem Demos Side 2 #1 Water Gas; #2 Hydrogen Chlorine Cannon; 2nd Day Rxn Profile Diagrams N2/I2