Kinetics Challenge Problem
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 10-3M 1.0
4.52 x 10-3M 1.5
2.23 x 10-3M 2.3
4.76 x 10-4M 4.0
8.44 x 10-5M 5.7
2.75 x 10-5M 7.0
Experiment 2:[Y]o= 4.5 M
[CH3X] Time(hr)
4.50 x 10-3M 0
1.70 x 10-3M 1.0
4.19 x 10-4M 2.5
1.11 x 10-4M 4.0
2.81 x 10-5M 5.5
Experiments were also run at 85oC,. The value of the rate constant at 85oC was found to be 7.88 x 108 hrs., where [CH3X]o = 1.0 x 10-2M and [Y]o = 3.0 M
a- Determine the rate law and the value of k for the reaction at 25oC
b- Determine the half-life at 85oC
c- Determine Ea for the reaction
d- Given that the C?X bond energy is 320 Kj/mol, suggest a mechanism that explains the results in parts a and c