Water does not appear in the equilibrium expression because it is a pure liquid. However, the addition of water to the equilibria in this lab can impact the equilibrium. Why does this happen? The addition of water will cause a side reaction to occur The addition of water will always change the temperature of the solution The addition of water will always lower the pH of the solution The addition of water will change the concentration of the substances in equilibrium

The correct answer is: The addition of water will change the concentration of the substances in equilibrium.

Explanation:

For chemical reactions, the equilibrium constant is defined as the ratio between the concentration of products and reactants. In this expression pure substances should not be written, like pure liquids and gases. Since water is a pure liquid should not appear in the equilibrium. However, water is the solvent of all the solutes or substances in the reaction, thus the addition of water will make all the substances to be diluted. Also, because of the Le Châtelier principle the equilibrium should be re-establish and the concentrations whitten in the equilibrium constant should change too.