Chemical equilibrium refers to a state in which the concentration of both reactants and products are present in concentration which shows no tendency of changing with time. At this point there is no observable changes in the system. The chemical equilibrium will change to dynamic equilibrium once a reversible reaction occurs. In this case, the ratio of reactants or product changes but there are movements between the chemicals in such a way that there is no net change. At dynamic equilibrium, reactant and products are formed in a rate that keep the concentration of both constant.
