## k1 vs k2?

$aR \to bP, Rate = -\frac{1}{a} \frac{d[R]}{dt} = \frac{1}{b}\frac{d[P]}{dt}$

inlovewithchemistry
Posts: 104
Joined: Fri Sep 28, 2018 12:19 am

### k1 vs k2?

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?

Marina Gollas 1A
Posts: 36
Joined: Fri Sep 28, 2018 12:20 am

### Re: k1 vs k2?

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?:)

chaggard
Posts: 37
Joined: Fri Sep 28, 2018 12:19 am

### Re: k1 vs k2?

K's differ based on different reactions. The question is only about 1 reaction. Therefore there is only one reaction rate constant, K.

Courtney Quan 1C
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Joined: Fri Sep 28, 2018 12:26 am
Been upvoted: 2 times

### Re: k1 vs k2?

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.

Rhea Churi 4K
Posts: 62
Joined: Fri Sep 28, 2018 12:28 am

### Re: k1 vs k2?

K changes when it is a different reaction or the same reaction is performed at a different temperature.