The concentrations of pure solids or pure liquids involved in a chemical reaction are not included in the equilibrium expression for the reaction.

Question

Quizplus · Accepted Answer

This is known as the "equilibrium constant expression" or "equilibrium law," and it only includes the concentrations of the reactants and products that are in the gas or aqueous phase. The reason for this is that the concentrations of pure solids and liquids do not change during the reaction, so they do not have an effect on the equilibrium position.

The Concentrations of Pure Solids or Pure Liquids Involved in a Chemical