## Kp and Kc

$PV=nRT$

Dang Lam
Posts: 55
Joined: Thu Jul 27, 2017 3:01 am

### Kp and Kc

What is the differences between Kp and Kc? Can someone help?

Suchita 2I
Posts: 59
Joined: Fri Sep 29, 2017 7:04 am

### Re: Kp and Kc

Kc and Kp are both equilibrium constants used for gas-phase mixtures. However while Kc uses molar concentration of the gases, Kp uses partial pressure of the gases involved.

Girija_3E
Posts: 27
Joined: Fri Sep 29, 2017 7:07 am
Been upvoted: 1 time

### Re: Kp and Kc

While this is not a difference, also keep in mind that you calculate both of them the same way, with the products on the top and the reactants on the bottom!

AtreyiMitra2L
Posts: 169
Joined: Fri Sep 29, 2017 7:03 am
Been upvoted: 1 time

### Re: Kp and Kc

The former is referring to the partial pressures and the latter is referring to molarity. You use the former with gases and the latter with gases and aqueous solutions.

Katherine Jordak 1H
Posts: 51
Joined: Fri Sep 29, 2017 7:05 am

### Re: Kp and Kc

Is it possible to use Kc when only gases are involved in the reaction? If so, how do you know when to use Kp and when to use Kc?

Katherine Jordak 1H
Posts: 51
Joined: Fri Sep 29, 2017 7:05 am

### Re: Kp and Kc

Is it possible to use Kc when only gases are involved in the reaction? If so, how do you know when to use Kp and when to use Kc?

Ashley Fallon 3C
Posts: 18
Joined: Fri Sep 29, 2017 7:06 am
Been upvoted: 1 time

### Re: Kp and Kc

Kc uses molar concentrations while Kp uses the partial pressures of gasses inside the closed system

Yuting Zhu 3D
Posts: 17
Joined: Tue Oct 10, 2017 7:14 am

### Re: Kp and Kc

I think it just depends on the facts you are given in the problem. When you are given concentrations of gases, you are using Kc, while if you are given the partial pressures, then you should use Kp.