## Question 15.95

Arrhenius Equation: $\ln k = - \frac{E_{a}}{RT} + \ln A$

Ishan Saha 1L
Posts: 60
Joined: Fri Sep 29, 2017 7:03 am

### Question 15.95

For this problem, we are given a reaction profile. From this we can tell that there are three steps to the reaction. In part c we are told that a catalyst is added that accelerates the third step only. the question in part c asks, "What affect if any will the catalyst have on the rate of the overall reaction?"

The answer is none, but I had thought that it would speed up the overall rate as it is causing part of the overall reaction to accelerate speed. Can somebody please explain why it has no effect?

Thanks!

Rachel Formaker 1E
Posts: 86
Joined: Fri Sep 29, 2017 7:04 am
Been upvoted: 2 times

### Re: Question 15.95

Because the slow step is the rate-determining step, only changing the slow step will change the rate of the reaction.

Adding a catalyst to one of the fast steps will not affect the rate of reaction because the fast step does not determine the rate.