Final answer:
At chemical equilibrium, the rates of the forward and reverse reactions are equal, so the concentrations of reactants and products stay constant over time, creating a dynamic equilibrium. If equilibrium is disturbed, the system adjusts to establish a new equilibrium state.
Step-by-step explanation:
What Happens When a Chemical Reaction Reaches Equilibrium?
When a chemical reaction reaches equilibrium, it arrives at a state where the concentrations of reactants and products remain constant over time. This occurs because the forward reaction, in which reactants are converted into products, occurs at the same rate as the reverse reaction, where products revert to reactants. This balance of rates means that there are no net changes in the concentrations of the reactants and products, defining a condition known as a dynamic equilibrium.
Dynamic Nature of Chemical Equilibrium
It is important to note that reaching chemical equilibrium does not imply that the chemical reactions have stopped. On the contrary, it is a dynamic process where reactions continue to occur in both the forward and reverse directions. However, these reactions are in balance, so they do not alter the overall concentrations of the reactants and products which stay consistent over time.
Disturbance in Equilibrium
When an equilibrium is disturbed, for instance by adding a reactant or product, the system responds by shifting the equilibrium to minimize the disturbance. This phenomenon is encapsulated by Le Chatelier's principle. The reaction quotient will adjust, and a new equilibrium position will be established until the rate of the forward reaction once again equals the rate of the reverse reaction.