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Hour Exam II. Wednesday, March 15. 7:00 – 9:00 pm. 103 Mumford Hall AQG, AQI Allen AQJ Blair AQF. 150 Animal Science Fisher AQB, AQC Koys AGD Pearson AQA. conflict exam 4:30 – 6:30 162 Noyes. Kinetics. Thermodynamics :. spontaneity of reaction. G < 0 spontaneous.
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Hour Exam II Wednesday, March 15 7:00 – 9:00 pm 103 Mumford Hall AQG, AQI Allen AQJ Blair AQF 150 Animal Science Fisher AQB, AQC Koys AGD Pearson AQA conflict exam 4:30 – 6:30 162 Noyes
Kinetics Thermodynamics : spontaneity of reaction G < 0spontaneous 2H2(g) +O2(g) 2H2O(l) Go = -474 kJ Go = Ho- TSo a) low T b) high T Ho < 0 favorable So < 0 unfavorable Thermodynamically spontaneous very slow
thermodynamics thermodynamics Kinetics rates of reaction mechanism of reaction O2(g) 2 H2O(l) Greaction < 0 2 H2(g) + Greactants Gproducts kinetics
qn qe r + + Kinetics 2H2(g) + O2(g)2 H2O(l) Go = -474 kJ spontaneous P.E.n-e - +
+ + High Temperature exothermic endothermic
Kinetics rate of reaction [reactant] decrease increase [product] 1. Temperature (K.E.) 2. Concentration 3. Orientation
- 1 2 differential rate laws A + B C - d[A] = d[C] dt d[B] = dt a) + b) - + rate = dt A + B 2 C - d[A] = dt d[C] dt -d[B] = dt rate = A + B C +
100 [ ] 50 0 1 2 3 4 5 time (min) [ ] = t -[ ] = t x t (min) 0 100 100 0 x 72 1 72 28 x 2 52 52 48 x x 3 37 37 63 x 4 27 27 73 5 19 19 81 81 - 0 = 16.2 min-1 ave. rate = 5 - 0 (19 ) - 100 ave. rate = - = 16.2 min-1 5 - 0
x 100 t (min) 0 100 100 0 x [ ] 72 1 72 28 x 50 2 52 52 48 x x 3 37 37 63 x 4 27 27 73 0 5 19 19 81 1 2 3 4 5 time (min) overall ave. rate = - (19 - 100) = 16.2 min-1 5 - 0 1st minute ave. rate = = 28.0 min-1 - (72 ) - 100 1 - 0 5th minute ave. rate = - 27) = 8.0 min-1 - (19 5 - 4
x 100 x [ ] x 50 x x x 0 1 2 3 4 5 time (min) instantaneous rate slope of line tangent to curve = at t = 0 initial rate fastest rate
t instantaneous (min) rate k = rate [reactant] 100 33.0 0 0.33 1 72 23.8 2 52 17.2 3 37 12.2 4 27 8.9 5 19 6.3 0.33 0.33 0.33 0.33 0.33 rate [reactant] = k [reactant] k = rate constant
k = rate [reactant] k independent of [reactants] dependent on Temperature k [A]a [B]b [C]c ... (-d[A]) k rate = = dt k, a, b and c determined experimentally isolation method
[A] [A] Concentration (M) Concentration (M) t (ms) t (ms) Exp. 1 [B]i initial rate [A]i (M) (M) (M s-1) 1.0 1.0 1.0 x 10-3 Exp. 2 [A]i [B]I initial rate (M)(M)(M s-1) 2.0 1.0 2.0 x 10-3 Exp. 3 [A]i [B]I initial rate (M)(M)(M s-1) 1.0 x 10-3 1.0 2.0
Exp. 1 k rate = [A]a [B]b [A]i [B]I initial rate (M)(M)(M s-1) 1.0 1.0 a = 0 a = 1 a = 2 2 x 10-3 = 1 x 10-3 [2.0]a [1.0]a rate 2 = rate 1 1.0 x 10-3 Exp. 2 1 x 10-3 = 1 x 10-3 rate 3 = rate 1 [2.0]b [1.0]b b = 0 b = 1 b = 2 [A]i [B]I initial rate (M)(M)(M s-1) 2.0 1.0 rate = k [A] 2.0 x 10-3 1storder reaction Exp. 3 [A]i [B]I initial rate (M)(M)(M s-1) 1.0 2.0 1x10-3(M s-1) = k [1.0 M] k = 1 x 10-3 s-1 1.0 x 10-3