Difference Between Kp and Kc

Jennifer1E
Posts: 25
Joined: Fri Jun 23, 2017 11:39 am

Difference Between Kp and Kc

What is the essential difference between Kp and Kc?

Kyle Sheu 1C
Posts: 87
Joined: Fri Jun 23, 2017 11:39 am

Re: Difference Between Kp and Kc

Kp is an equilibrium involving the partial pressures of the gases involved, whereas Kc (for the same gaseous reaction) is an equilibrium involving the concentrations of the gases.
In the former, we would use partial pressure=(nRT)/V, while in the latter, we would have M=n/V=P/(RT).

When solving for Kp, you would substitute in the values for partial pressure as you would for any other equilibrium question.

Yeyang Zu 2J
Posts: 58
Joined: Fri Sep 29, 2017 7:06 am

Re: Difference Between Kp and Kc

Kc And Kp. K and K are the equilibrium constants of gaseous mixtures. However, the difference between the two constants is that Kc is defined by molar concentrations, whereas Kp is defined by the partial pressures of the gasses inside a closed system

Alex Leve 3F
Posts: 20
Joined: Fri Sep 29, 2017 7:07 am

Re: Difference Between Kp and Kc

If you are confused on knowing when to use which one, you just need to know that you can only use Kp when there is one or more gaseous product or reactant and no aqueous products or reactants.

Essly Mendoza 1J
Posts: 25
Joined: Fri Sep 29, 2017 7:04 am

Re: Difference Between Kp and Kc

How are the equilibrium expression K and the equilibrium expression Kc different? Thank you.