Consider the following reaction:
CH3X + Y --> CH3Y + X
At 25ºC, the following two experiments were run, yielding the following data:
Experiment 1: [Y]0 = 3.0 M
[CH3X] Time (hr)
7.08 x 10-3 M 1.0
4.52 x 10-3 M 1.5
2.23 x 10-3 M 2.3
4.76 x 10-4 M 4.0
8.44 x 10-5 M 5.7
2.75 x 10-5 M 7.0
Experiment 2: [Y]0 = 4.5 M
[CH3X] Time (hr)
[CH3X] 0
1.70 x 10-3 M 1.0
4.19 x 10-4 M 2.5
AP Chemistry homework Kinetics
Due by 7:45 AM to Mrs. Scherr on Wednesday, Feb 22, 2012
1.11 x 10-4 M 4.0
2.81 x 10-5 M 5.5
Both experiments were run at 85ºC. The value of the rate constant at this temperature
was found to be 7.88 x 108 (with the time in hours), where [CH3X]0 = 1.0 x 10-2 M and
[Y]0 = 3.0 M
(a) Determine the rate law and value for k for this reaction at 25°C.
(b) Determine the half-life at 85°C.
(c) Determine the activation energy, Ea for the reaction.
(d) Given that the C-x bond energy is known to be about 325 kJ/mol, suggest a
mechanism that explains the results in parts (a) and (c