Intermediates [ENDORSED]

[Caroline C 1G]

Does the concentration of an intermediate always have an affect on the reaction rate?

[Eli Aminpour 2K]

today we talked in class about how when reactions are coupled, one of the steps may go so much faster than the other step that the overall reaction speed is determined by the slower step. The intermediate's concentration in this case wouldn't affect the overall reaction

[Vincent Tse 1K]

Yeah, Eli's right! Unless, of course, the intermediate IS part of the rate-determining step. It kind of depends on the reaction, really--for a coupled reaction, just look for the slowest one.
Unless they themselves are part of the rate-determining step, intermediates have little function on the reaction rate of an overall mechanism.