rate law for forward and backward reaction

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

Aijun Zhang 1D
Posts: 53
Joined: Tue Oct 10, 2017 7:13 am

rate law for forward and backward reaction

A quick question:
Dr. Lavelle mentioned in class that we considered only forward reaction. Why would we not consider the backward reaction although some of the products will return to the reactant?
Thanks!

Nora 1F
Posts: 46
Joined: Fri Sep 29, 2017 7:04 am

Re: rate law for forward and backward reaction

I believe this was referring to when the concentration of product is low, because when the product concentration is low it is less likely that the backward reaction will be occurring at a significant rate.

Jason Liu 1C
Posts: 52
Joined: Fri Sep 29, 2017 7:04 am

Re: rate law for forward and backward reaction

We are looking to find the rate of reaction immediately after the reaction starts. This means that none of the reactants have turned into product yet, which is why we can focus only on the forward reaction. Once there is product causing the reverse reaction, it is hard to find the rate of reaction. This is explained in more detail on page 617 in the book.