Dynamic equilibrium is a state of balance between continuing processes. It exists once a reversible reaction stops changing its proportion of reactants and/or products, but substances move between the chemicals at an equal rate, implying that there is no net change. Dynamic equilibrium is an illustration of a system in a steady state.
Equilibrium refers to the state of equal opposite rates. The reaction rates of the forward and reverse reactions are equal. The concentrations of the reactants and products are constant, but not necessarily equal. There are two forms of equilibrium: dynamic equilibrium and static equilibrium. In a dynamic equilibrium, the reaction rate of the forward reaction is equal to the reaction rate of the backward reaction. Reactants are transformed into products and products are transformed into reactants at an equal and constant rate. An example of a dynamic equilibrium is what occurs with acid-base equilibrium, including the dissociation of acetic acid in aqueous solution.
Statistic equilibrium, also known as mechanical equilibrium, occurs when all substances in the reaction are at rest and there is no motion between reactants and products. It can also be considered as a steady-state system in a physical-based view. In static equilibrium, dynamic forces do not act on the potential energies of the forward and backward reaction. The process of graphite turning into diamond is an example of static equilibrium because there are no forces acting upon graphite, which is the reactant, and diamond, which is the product, after it occurs.