1. Chemical Kinetics or Reaction Rates

2. You have 6 ball bearings with identical magnetic strength but different diameters where A > B > C > D > E > K. Which two will hold together the most & the least.

3. Reaction Rate
The speed at which reactants become products in a chemical reaction
M/s

4. Kinetic Theory All matter is made up of tiny particles
The particles are in constant motion
All collisions are elastic ?

5. Elastic Collisions
Collisions in which there is no energy change

6. Particles Reacting For particles to react, they must collide
Reaction rate is dependent on collision rate

7. Particles Reacting
When a reaction takes place, an energy change occurs
Collisions (in which reactions occur) are not elastic

10. Reaction Rate
Rate = - d[Reactant]/dt
Rate = +d[Product]/dt
M/s

13. Factors Affecting Rxn Rate
Concentration, Temperature, Agitation, Process, Orientation, Catalyst, SA of Solid, Pressure of Gas, Reaction Mechanism

14. List & describe all of the factors affecting rxn rates.

16. Drill:
List at least 5 factors that will affect reaction rates

17. Rate Expression
An equation showing how rate depends on the amount of reactants in a rate determining reaction

18. Rate Expression Rxn: aA(aq) + bB(aq) P Expr: Rate = k[A]a[B]b
[A] = molarity of A

19. Rate Expression
Rxn: aA(g) + bB(g)
Product
Exp: Rate = kPAaPBb

20. Write Rate Expressions for:
H2(g) + N2(g) NH3(g)
HCl(aq) + Ba(OH)2(aq)
BaCl2(aq) + H2O (l)

21. Write Rate Expressions for:
Cl2(g) + HOOH (aq)
P(aq)

22. Reaction Order The total number of reactants
Equals total of all of the coeffecients of R in the rxn
Equals total exponents in rate expression

23. Determining Rxn Rate Find rate expression ratios
(Ratio of concentrations)x = rate ratio
x = exponent

24. Experimental Results Exp [A] [B] [C] Rate 1 1.0 1.0 1.0 2

25. Experimental Results Exp # [A] [B] [C] Rate 1 0.1 0.1 0.1 3

26. Experimental Results Exp # [R] [S] [T] Rate 1) 0.25 0.20 0.10 21) 2) 3) 4)

27. Half-Life
The time required for one half of a reactant to be decomposed in a reaction

29. Useful Relationships
Rxn Order Rate Exp
R=k
R=k[A]
R=k[A]2

30. Useful Relationships
Rxn Order Half Life
0 [Ao]/2k /k
/k[A]

31. 1st Order Age Dating Formula
t = ln(Ai/Af)t1/2
0.693

32. Useful Relationships Rxn Order Lin Plot 0 [A] vs k 1 ln[A] vs k

33. Useful Relationships Rxn Order Calc R E 0 -d[A]/dt = k
d[A]/dt = k[A]
d[A]/dt = k[A]2

35. Clausius-Claperon Eq
(T2)(T1) k2
(T2 – T1) k1
Ea= R ln

37. Calculate the activation energy of a reaction whose rate constant is 2
Calculate the activation energy of a reaction whose rate constant is 2.0 x 103 at 27oC and is 2.0 x 106 at 77oC:

38. Experimental Results Exp # T [A] [B] Rate 1) 27oC 0.10 0.10 2

39. The sequence of steps that make up the reaction process
Reaction Mechanism
The sequence of steps that make up the reaction process

41. Reaction Mechanism Step 1 A <--> B fast Step 2 B ---> C slow
Step 3 C <--> D fast
Total A ---> D

42. The rate determining step in a reaction mechanism is the slowest step

43. To solve the rate expression, you must use the slowest step
Reaction Mechanism
To solve the rate expression, you must use the slowest step

44. Solve Rate Expression A + B C + D fast 2C + A G fast 2D + B K fast
2G + 2K Prod. slow

45. Solve Rate Expression X + Y M + N fast M + N 2G slow 2N + G K fast
2G + 2K Prod. fast

46. Solve Rate Expression X + Y M + N fast 3M + N 2G fast 2N K fast
4G + 2K Prod. slow

47. Solve Rate Expression A + B C + D fast 4C + A 2G fast 4D + B 2K fast
G + K Q + W slow
Q + W Prod. fast

48. Review

49. Experimental Results Exp # T [A] [B] Rate 1) 27oC 0.10 0.10 2

50. Solve Rate Expression A + B C + D fast 4 C + A 2G fast 2 K 4D + B fast
G + K Q + W fast
2Q + 2W Prod. slow