## How Balancing Affects Rate Law

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

Albert Chong_1L
Posts: 77
Joined: Fri Sep 25, 2015 3:00 am

### How Balancing Affects Rate Law

Hi,

I was wondering if equations should be balanced before rate laws are derived.

That is, for Question 3 of Quiz Prep 2, the question states that rate=k[N2O]...

However, when the reaction in question is balanced, N2O has a 2 coefficient.

Does this not change the rate equation to become rate=k[N2O]^2 since it is bimolecular?

104422816
Posts: 17
Joined: Fri Sep 25, 2015 3:00 am

### Re: How Balancing Affects Rate Law

Hi! For the rate law equations you don't use the stoichiometric coefficient because you don't necessarily know that that is the coefficient throughout all of the steps in the reaction is 2. Because you know that it is first order, you only take it to the power of 1.