Select the statements below that are true kc and kp are the same thing as the k (rate constant) that you learned about before. kp uses the same equation as kc, but with pressure instead of concentration kc is equal to kp when the number of moles of gas (n) doesn't change. solids and pure liquids are not included in the kc and kp equations because they have an activity equal to 1 if there is a liquid in a reaction, you use the vapor pressure for that entry in the kp equation. kc has units of molarity and kp has units of pressure