[Pinoylegacy]

The overall rate of any chemical reaction is most closely related to

a)the number of steps in the reaction mechanism
b)the overall reaction
c)the fastest step in the reaction mechanism
d)the slowest step in the reaction mechanism
e) the average rate of all the steps in the reaction mechanism

I think it's d) but my friends are saying e). What should be the answer and why?

[Schrödinger]

d) is correct. Supported by : http://en.wikipedia.org/wiki/Rate-determining_step

[opti384]

An easy analogy will be the traffic. Let's say it takes an hour from A to C. However, between A and C there is also a point B which takes 57 minutes due to heavy traffic. From B to C it takes only 3 minutes. Here we can say that the time required to move from A to C is almost determined by the 57 minutes travel from A to B because it takes almost an hour. Likewise, the slowest step in the reaction mechanism determines the overall rate.