## Slow vs Fast Step

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

Tiffany_Cacy_3D
Posts: 70
Joined: Fri Sep 28, 2018 12:24 am

### Slow vs Fast Step

How do you tell which step in a multistep reaction is the slow step? Would we be given this information or is there a way to tell by the step itself? I am having trouble figuring out which step is the rate limiting step.

Mindy Kim 4C
Posts: 65
Joined: Fri Sep 28, 2018 12:25 am

### Re: Slow vs Fast Step

Normally the problem will either tell you which step is the slow, rate determining step, or it will give you the reaction mechanism and the overall rate law for the reaction and you would have to determine from this information which step is the slow step.

Searra Harding 4I
Posts: 68
Joined: Fri Sep 28, 2018 12:29 am

### Re: Slow vs Fast Step

The slow step is always the rate determining step. So the rate of this step will be the overall rate.

anthony_trieu2L
Posts: 60
Joined: Fri Sep 28, 2018 12:29 am

### Re: Slow vs Fast Step

If the slow step is the not first step and contains and intermediate, you can assume the first step is at equilibrium and use the pre-equilibrium approach.

Noh_Jasmine_1J
Posts: 71
Joined: Fri Sep 28, 2018 12:15 am

### Re: Slow vs Fast Step

the slow step usually has the same rate as the observed rate