What effect does changing the concentration of a reactant have on a reversible reaction?

Changing the concentration of a reactant in a reversible reaction impacts the system's position of equilibrium. According to Le Chatelier's principle, if the concentration of a reactant is increased, the system will adjust to counteract this change by favoring the forward reaction, leading to more products being formed. This results in the concentrations of the substances shifting until a new equilibrium is established.

This dynamic ensures that the concentrations of both reactants and products will adjust in response to the change in reactant concentration. As a result, the concentration of all substances in the reaction will change until the system reaches a new state of equilibrium. This principle helps to predict how the system reacts to different changes, ensuring that a consistent balance can be maintained.