Determining the Rate Law fora Multistep MechanismThe

Chapter , Problem 1PE

(choose chapter or problem)

Problem 1PE

Determining the Rate Law fora Multistep Mechanism

The decomposition of nitrous oxide. N20. is believed to occur by a two-step mechanism: N20(g)→N2(g) + O(g) (slow)

N20(g) + O(g)→N2(g) + O2(g) (fast)

(a) Write the equation for the overall reaction, (b) Write the rate law for the overall reaction.

Let’s consider a hypothetical reaction similar to that in Practice Exercise 1 of Sample Exercise 14.13: 2 C + D→J + 2 K. You are told that the rate of this reaction is second order overall and second order in [C]. Could any of the following be a rate-determining first step in a reaction mechanism that is consistent with the observed rate law for the reaction (note that substance Z is an intermediate)?

(a) C + C→K + Z (b) C→J + Z (c) C + D→J + Z (d) D→J + K (e) None of these are consistent with the observed rate law.