[Kuahji]

Does anyone know where I can find a good guide to rate mechanisms?  I'm having a lot of trouble trying to figure out if an elementary is slow or fast or how everything is related. 

Here is an example question
When the concentration of A is doubled, the rate for the reaction: 2 A + B-> 2 C quadruples.  When the concentration of B is doubled the rate remains the same.  Which mechanism below is consistent with the experiment observations? 
The answer is (it was multiple choice, but I'll just post the correct answer)
Step 1: 2A -> D (slow)
Step 2: B + D -> E (fast)
Step 3: E-> 2 C (fast)

So I just look at it & wonder how...  I just don't get it. 

[rascal]

I think that statement, When the concentration of B is doubled the rate remains the same.", implies that B is not a reagent in the rate-determining step, which is the elementary step that has the slowest rate. And "When the concentration of A is doubled, the rate for the reaction: 2 A + B-> 2 C quadruples" implies that the stoichiometric coefficient of A is twice, according to the Rate Law.

So the rate law is probably like ... Rate = [A]²

Find out more about the topic: try http://en.wikipedia.org/wiki/Reaction_rate

P.S. I don't speak English so my skills are poor. Hope you understand me.