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### k1 vs k2?

Posted: Wed Mar 13, 2019 10:37 pm
if not specified, do we assume that k is a constant?
i was doing the fast equilibrium method and my answer was rate=k2K[NOCl]^2/[NO], but the correct answer was rate=k[NOCl]^2/[NO].
from this, i can assume k was a constant in the mechanism, correct?

### Re: k1 vs k2?

Posted: Thu Mar 14, 2019 3:30 am
In response to your question, I am going to ask a question to understand your thoughts and approach. How did you get "k2k" in your rate law for "rate=k2K[NOCl]^2/[NO]"? Since I believe that K would be a constant perhaps representing that value of "K2K", however I believe it should be something like "K2/K" or perhaps even "K1/K-1"? Or did the question that you got this answer for state otherwise?:)

### Re: k1 vs k2?

Posted: Thu Mar 14, 2019 9:59 am
K's differ based on different reactions. The question is only about 1 reaction. Therefore there is only one reaction rate constant, K.

### Re: k1 vs k2?

Posted: Thu Mar 14, 2019 11:17 am
For a specific reaction at a specific temperature, there is only one rate constant k. However, if this same reaction took place at a different temperature, k would change. Note that there are different rate constant k's for different reactions.

### Re: k1 vs k2?

Posted: Thu Mar 14, 2019 12:29 pm
K changes when it is a different reaction or the same reaction is performed at a different temperature.