Kc vs Kp

[Bijan Mehdizadeh 1B]

If we are asked to find K, do we assume it is Kc or Kp?

[Reva Kakaria 1J]

I believe it depends on what you are given: if you are given the concentrations of the molecules in the chemical reaction, then it's Kc, and if you are given the partial pressures, you have to find Kp.

[Fanny Lee 2K]

When you're given both units of concentration and units of pressure in an equilibrium equation, you must convert the units of pressure into units of concentration using the ideal gas law.

[Brian Hom 2F]

It just depends on what the problem gives you and what it is asking for. If we need to find partial pressures we are dealing with Kp but if we need to find concentrations we are dealing with Kc.

[Adrian C 1D]

It important also to take note of the states of the reactants and products. For example, if you have only gases you are probably using partial pressures and therefore Kp.