KP versus KC

[Gurvardaan Bal1L]

I understand that there are two different forms of the equilibrium constant equations and that they are calculated with molarity and partial pressure(respectively), but is there any difference as to how they are interpreted? Today in lecture Professor Lavelle talked a little bit about this with the values of K determining whether the reaction equilibrium lied to the left or right, but was that in regard to partial pressure, molarity, or both?

[Wayland Leung]

They represent the same thing. Normally we would just call it k. It is up to you to figure out if we are trying to find concentrations or pressure. But the equilibrium constant is the same in both cases.

[Rachel Formaker 1E]

Both types of equilibrium constant, whether in regard to molarity or partial pressure, refer to the composition of the equilibrium. Either constant will tell you if the equilibrium sits to the left or to the right.

[Andrea ORiordan 1L]

The only way Kp is different than Kc is in the units. You can also convert Kp to Kc fairly easily, and therefore it makes sense that they represent effectively the same thing. Kp is used for simplicity in equations only utilizing gases.