## Determining overall rate order

torialmquist1F
Posts: 49
Joined: Sat Jul 22, 2017 3:00 am

### Determining overall rate order

Are only the rate orders of reactants relevant in the overall rate order? Do rate orders of products even exist, or only in the reverse reactions?

Curtis Tam 1J
Posts: 105
Joined: Thu Jul 13, 2017 3:00 am

### Re: Determining overall rate order

I'm pretty sure they do exist for products but the point of a rate law is to simplify the reaction so that we are only studying its rate based on the reactants because the concentration of products could affect the rate of reactant consumption.

Lisa Tang 1C
Posts: 62
Joined: Fri Sep 29, 2017 7:05 am
Been upvoted: 2 times

### Re: Determining overall rate order

Sometimes the presence of products does affect the reaction order, but I believe that we aren't really going to deal too much with that in this class. An example of this can be found on page 621 of the textbook in case you wanted to know more!

Yashaswi Dis 1K
Posts: 56
Joined: Fri Sep 29, 2017 7:04 am

### Re: Determining overall rate order

Well, rate is usually considered in terms of the consumption of reactants which is easier to measure. So if you had A + B <----> C + D, a hypothetical forward reaction's rate law would like rate = k[A][B], for example. For the reverse reaction, where the reaction mechanism does not change, now it will be
C + D <-----> A + B so the products initially in the forward reaction are the reactants for the reverse reaction. So you are technically still using the reactants for the reverse reaction. Hypothetically, a rate law for the reverse reaction that was first mentioned above, is Rate = k'[C][D].

Hope that helps!