The point that reactions go to completion is not a characteristic of chemical equilibrium. Chemical equilibrium is the state in which both reactants and products are present in concentrations which have no further tendency to change with time. At this point the rate of the forward reaction equals the rate of the backward reaction. Characteristics of equilibrium include; they occur in reversible reactions, there is no net change in concentrations of reactants and products, and also the forward and reverse rates are the same.