Consider the following reaction: CH3X 1 Y 88n CH3Y 1 X At

Chapter 15, Problem 15.127

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Consider the following reaction: CH3X 1 Y 88n CH3Y 1 X At 258C the following two experiments were run, yielding the following data: Experiment 1: [Y]0 5 3.0 M [CH3X] Time (h) 7.08 3 1023 M 1.0 4.52 3 1023 M 1.5 2.23 3 1023 M 2.3 4.76 3 1024 M 4.0 8.44 3 1025 M 5.7 2.75 3 1025 M 7.0 Experiment 2: [Y]0 5 4.5 M [CH3X] Time (h) 4.50 3 1023 M 0 1.70 3 1023 M 1.0 4.19 3 1024 M 2.5 1.11 3 1024 M 4.0 2.81 3 1025 M 5.5 Experiments were also run at 858C. The value of the rate constant at 858C was found to be 7.88 3 108 (with the time in units of hours), where [CH3X]0 5 1.0 3 1022 M and [Y]0 5 3.0 M. a. Determine the rate law and the value of k for this reaction at 258C. b. Determine the half-life at 858C. c. Determine Ea for the reaction. d. Given that the COX bond energy is known to be about 325 kJ/mol, suggest a mechanism that explains the results in parts a and c.