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
MAKING FIREWORKS/EXPLOSIONS
FIRE !!
MAKING GASOLINE/PETROLEUM PRODUCTS
RUSTING CORRISION
HW 11-1, p. 101, Part 1, #1

2. MANY DRUGS WORK BY STOPPING REACTIONS
Penicillin Antibiotics-kill bacteria by blocking the enzyme catalyzed reaction that builds cell walls in bacteria.
Human cells have membranes, not cell walls. Stopping this chemical reaction that bacteria need but people don’t has saved thousands of lives.

3. HW 11-1 #2 – ways to speed up or slow down reactions
STIRRING
INCREASE CONCENTRATION OF REACTANTS (or pressure of a gas system)
INCREASE SURFACE AREA
INCREASE TEMPERATURE
ADD A CATALYST
DECREASE CONC.
DECREASE SURFACE AREA
DECREASE TEMPERATURE
ADD INHIBITOR

4. Developing an atomic level model for reactions
WHY DOES STIRRING IMPACT REACTION RATE OR RATE OF DISSOLVING?

5. Hint: Stirring = increasing movement of solute and solvent particles
How could increasing agitation (movement) speed impact the interactions between solute and solvent molecules?

6. Why does stirring increase dissolving rate?
Agitating the solution carries away dissolved solute molecules and allows new solvent molecules to have access to needed more quickly make contact with undissolved solute particles.

7. Effect of concentration elephant toothpaste rxn
Link elephant toothpaste
4) In the first experiment with the green food coloring the hydrogen peroxide is a at a lower concentration. In the second experiment with the red food coloring the hydrogen peroxide is a a higher concentration. Which is faster?
ANS: Higher concentration = Faster Reaction

8. Part 4: #5 iodine clock reaction
Link to Clock Rxn Conc
H2O2 + KI + H+ + Starch + Na2S2O3→ H2O + Starch/I3 - (black) Equation is NOT balanced
Expt #1: [KI] = 0.3 M,
Expt #2: [KI] = 0.6 M, all other concentration held constant in both expts
5A) Independent variable = concentration of KI
5B) Dependent variable = time to color change (rxn rate)
5C) Constant: Concentrations of all other reactants and temperature

9. 5d) How DOES CHANGING CONCENTRATION IMPACT REACTION RATE?
INCREASING CONCENTRATION INCREASES REACTION RATE
WHY? WHAT IS HAPPENING ON THE MOLECULAR LEVEL?
Link to Collision Theory Animation II

10. 5e) In order to reactant molecules must first collide
5e) In order to reactant molecules must first collide. Increasing Concentration Increases # of Collisions
ANSWER 7F AND 7G ON TOP OF p. 99 (Misnumbered, should be 5f and 5g)

11. 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

12. which of the reactions below will be faster (LEFT OR RIGHT) and why?
HW 11-1, p. 99 Part 5,
Increasing surface area of solids increases reaction rate by increasing number of collsions

13. Which has more surface area, a strip of iron or steel wool
Which has more surface area, a strip of iron or steel wool? Which reacts more quickly with oxygen?
video link steel wool SA

14. Which burns more quickly: A pile of cornstarch or blown powder?
Video corn flower SA

15. Is collidING ENOUGH, I.E. Do ALL COLLISIONS PRODUCE A REACTION?
Link to Phet Simulation

16. Reaction requires collisions in the correct orientation
The two specific atoms in the different molecules that are reacting have to collide in the correct orientation.
HW 11-1 Part 6
Link to animation

17. HW 11-1, #11 BC
AB (or BA)

18. HW 11-1: Part 12 energy of collisions
Link to Phet Simulation
12A) Does each correctly oriented collision produce a rxn? 12B) In addition to the correct orientation, what other property of the collision is essential in order for the reaction to take place? 12C) Activation Energy, Ea = amount of necessary to initiate a chemical reaction. NO
ENERGY OF COLLISIONS
MINIMUM
ENERGY

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

20. Hw 11-1, #12

21. HW 11-1, #13
Activation Energy, Ea
Energy Change, ∆ E

22. Hw 11-1, #14 2 6

23. Height of Ea determines rxn rate; The LOWER the ea, THE GREATER THE NUMBER OF molecules that have energy (e) ≥ eA LOWER Ea = faster rxn