1. Drill: Calculate the osmotic pressure of 5.0 g NaOH in 7500 mL soln at 27 o C.

2. Drill: Calculate the heat change when 25.0 g of H 2 O goes from 66.3 o C to 26.3 o C. C water = 4.18 J/gK

3. Chemical Kinetics or Reaction Rates

4. Reaction Rate The speed at which reactants become products in a chemical reaction M/s = mole/Ls

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

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

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

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

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

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

13. Drill: List & describe at least 5 factors that will affect reaction rates

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

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

17. Rate Expression Rxn: aA (g) + bB (g) Product Exp: Rate = kP A a P B b

18. Write Rate Expressions for: H 2(g) + N 2(g) NH 3(g) HCl (aq) + Ba(OH) 2(aq) BaCl 2(aq) + H 2 O (l)

19. Write Rate Expressions for: H 2(g) + N 2(g) NH 3(g) Rate = k(P H2 ) 3 (P N2 )

20. Write Rate Expressions for: 2HCl (aq) + 1Ba(OH) 2(aq) 1BaCl 2(aq) + 2H 2 O (l) Rate = k[HCl] 2 [Ba(OH) 2 ]

21. Write Rate Expressions for: 1 Cl 2(g) + 1 HOOH (aq) 2 HOCl (aq)

22. Write Rate Expressions for: 1 Cl 2(g) + 1 HOOH (aq) 2 HOCl (aq) Rate = k(P Cl2 ) or Rate = k[HOOH]

23. Write the Rate Law for: 2A (aq) + B (aq) + 3C (s) Products

24. Write the Rate Law for: 2A (aq) + B (aq) + 3C (s) P Rate = k[A] 2 [B]

25. Reaction Order The total number of reactants (coefficients) Equals total exponents in rate expression

26. Drill: Write the rate expression & determine rxn order for: SO 2(g) + O 2 (g) SO 3(g)

27. Drill: Write the rate expression & determine rxn order for: 2 SO 2(g) + 1 O 2 (g) 2 SO 3(g) Rate = k(P SO2 ) 2 (P O2 )

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

29. Write the rate expression for: aA + bB Products All aqueous

30. The next slide includes data from an experiment where various concentrations of A & B were added together, and the rates of product formation was measured.

31. Experimental Results Exp [A] [B] Rate 1 1.0 1.0 2 2 2.0 1.0 4 3 1.0 2.0 8

32. Experimental Results Exp [A] [B] Rate 1 1.0 1.0 2 2 2.0 1.0 4 3 1.0 2.0 8

33. Write the rate expression for: aA + bB + cC Products All aqueous

34. Experimental Results Exp # [A] [B] [C] Rate 1 0.1 0.1 0.1 3 2 0.3 0.1 0.1 81 3 0.1 0.3 0.1 27 4 0.1 0.1 0.3 3

35. Experimental Results Exp # [A] [B] [C] Rate 1 0.1 0.1 0.1 3 2 0.3 0.1 0.1 81 3 0.1 0.3 0.1 27 4 0.1 0.1 0.3 3

36. Solve All: Exp Data: Exp # [R] [S] [T] Rate 1) 0.25 0.20 0.10 2 2) 0.25 0.60 0.10 18 3) 0.50 0.20 0.10 4 4) 0.25 0.20 0.40 32

37. Solve All: Exp Data: Exp # [R] [S] [T] Rate 1) 0.25 0.20 0.10 2 2) 0.25 0.60 0.10 18 3) 0.50 0.20 0.10 4 4) 0.25 0.20 0.40 32

38. Drill: Solve All Exp Data: Exp # [R] [S] Rate 1) 0.25 0.20 2 2) 0.25 0.60 18 3) 0.50 0.20 4

39. Solve All: Exp Data: Exp # [R] [S] Rate 1) 0.25 0.20 2 2) 0.25 0.60 18 3) 0.50 0.20 4

40. Solving exponents with a calculator. A x = B

41. Log A x = log B xLog A = log B Thus:

42. x = Log B Log A

45. Clausius-Claperon Eq E a = R ln (T 2 )(T 1 ) k 2 (T 2 – T 1 ) k 1

46. Calculate the activation energy of a reaction whose rate constant is 2.0 x 10 3 at 27 o C and is 2.0 x 10 6 at 77 o C:

47. Drill: List & describe at least 5 factors that will affect reaction rates

48. Half-Life The time required for one half of the reactants to change into products in a reaction

50. Useful Relationships Rxn OrderRate Exp 0Rate = k 1 Rate = k[A] 2 Rate = k[A] 2

51. 1st Order Age Dating Formula t = ln(A i /A f )t 1/2 0.693

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

54. Reaction Mechanism Step 1A  Bfast Step 2B  Cslow Step 3C  Dfast Total A  D

55. Reaction Mechanism The rate determining step in a reaction mechanism is the slowest step

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

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

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

59. Solve All: Exp Data Exp # T [A] [B] Rate 1) 27 o C 0.10 0.10 2 2) 27 o C 0.30 0.10 18 3) 27 o C 0.10 0.20 4 4) 77 o C 0.10 0.10 20

61. Solving Rxn Exponent Rate 2 k [IO 3 - ] x [S 2 O 5 -2 ] y M/31 s k(0.10M) x (0.10M) y M/66 s k(0.10M) x (0.05M) y = =

63. [Z] Abs 640 0.10.66 0.0750.495 0.050.33 0.0250.165 0.010.066

65. Drill: Solve Rate Expr: X + Y M + N fast 3M + N 2G fast 2N K fast 2G + K Prod. slow

66. Rate Law & Net Rxn A + B C + Dfast 4C + A 2Gfast 4D + B 2Kfast G + K Q + Wslow Q + 2 WProd.fast

67. Review

68. Drill: Determine All Exp # T [A] [B] Rate 1) 27 o C 0.10 0.10 2 2) 27 o C 0.30 0.10 54 3) 27 o C 0.10 0.20 8 4) 77 o C 0.10 0.10 200

69. Solve Rate Expression A + B C + Dfast 4 C + A 2Gfast 2 K 4D + B fast G + K Q + Wfast 2Q + 2W Prod.slow