## pre equilibrium approach

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

Sanjana Borle 2K
Posts: 111
Joined: Fri Aug 09, 2019 12:15 am

### pre equilibrium approach

When using the pre equilibrium approach, how do we know which step we need to use to find Kc or the equilibrium constant? Is it always the first step?

Sjeffrey_1C
Posts: 108
Joined: Wed Feb 20, 2019 12:17 am

### Re: pre equilibrium approach

To find the equilibrium constant, you use the step who's product is the intermediate. So yes, this would always (I think) be the first step. This K will allow you to solve for the concentration of the intermediate in other terms so that you eventually solve for the rate of formation of the final product.

Sydney Myers 4I
Posts: 100
Joined: Fri Aug 09, 2019 12:17 am

### Re: pre equilibrium approach

You would need to find K for whatever step you're considering is at equilibrium. Whatever fast step happens before the slow step with the intermediate.