## Molecularity and the Coefficient of an Elementary Step

$K = \frac{k_{forward}}{k_{reverse}}$

Hannah Guo 3D
Posts: 56
Joined: Fri Sep 29, 2017 7:06 am

### Molecularity and the Coefficient of an Elementary Step

Is there any association between the molecularity and the coefficient of an elementary step. For example, when the molecularity is termolecular, does it mean that the coefficients of the reactants in a balanced elementary step add up to be 3?
Thank you!

Julie Steklof 1A
Posts: 50
Joined: Thu Jul 13, 2017 3:00 am

### Re: Molecularity and the Coefficient of an Elementary Step

Molecularity is the number of species involved in an elementary step. So yes, for example a termolecular elementary step would have to have three reactants colliding which is seen in a reaction in which the stoichiometric coefficients add up to three.

Yixin Angela Wang 2H
Posts: 51
Joined: Thu Jul 27, 2017 3:00 am

### Re: Molecularity and the Coefficient of an Elementary Step

Yes, I believe that's correct. Molecularity is the number of reactants in a particular step, so for example a reaction that requires 2 molecules of one compound and 1 molecule of another would be 2A+B--->product, and it should be termolecular.