19.2 The equilibrium constant Kp

• Kp is the equilibrium constant in terms of partial pressure and is commonly used for equilibria involving gases
• Mole fraction = number of moles/total number of moles in the gas mixture
• The partial pressure of a gas is the contribution of the gas to the total pressure
• Partial pressure = mole fraction x total pressure
• Kp only includes gases because only gases have partial pressures