Backward reaction - a reaction in which reactants are produced from products and goes from right to left in a reversible reaction

Closed system - a physical system which does not allow certain types of transfers in or out of the system

Dynamic equilibrium - where the reaction rate of the forward reaction is equal to the reaction rate of the backward reaction

Equilibrium - a state in which both reactants and products are present in concentrations which have no further tendency to change with time 

Equilibrium constant - A measure of the relative concentrations of the reactants and products of a reversible reaction at equilibrium

Equilibrium mixture - a mixture of products and reactants at equilibrium position

Forward reaction - a reaction in which products are produced from reactants and goes from left to right in a reversible reaction

Irreversible reaction - a chemical reaction occurs when reactants react with each other in unidirection

Reversible reaction - a chemical reaction that results in an equilibrium mixture of reactants and products

Static equilibrium - occurs when all particles in the reaction are at rest and there is no motion between reactants and products