## Overall Order of a Reaction

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

keyanabogan 2J
Posts: 17
Joined: Wed Sep 21, 2016 2:56 pm

### Overall Order of a Reaction

On page 621, it shows that the reaction of 2O3(g)->3O2(g) has a rate law of k([O3]^2/[O2]). I don't understand what happens to the coefficient of O2 in the rate law equation. Why doesn't O2 have a superscript of 3?

Josh Ku 3H
Posts: 25
Joined: Wed Sep 21, 2016 2:59 pm

### Re: Overall Order of a Reaction

On page 621 the rate law is experimentally determined. You cannot determine the rate law from the coefficients in the overall reaction, only from elementary steps as seen on page 70 in the course reader.

Hope this helps

samuelkharpatin2b
Posts: 55
Joined: Wed Sep 21, 2016 2:57 pm

### Re: Overall Order of a Reaction

In order to derive a rate law, you must compare experimental data or pay attention to the slow step in a given mechanism. There is no formula or anything like that where you can simply find the rate law without experimental data or the mechanism.