Chemical equilibrium
Chemical equilibrium is a state in which the rates of the forward and reverse reactions are equal and the concentrations of the reactants and products remain constant. Equilibrium is a dynamic process i.e. the conversions of reactants to products and products to reactants are still going on, although there is no net change in the number of reactant and product molecules.
Therefore the Chemical equilibrium can be defined two different ways: (i) It is the condition in which the concentrations of all reaction species do not change with time, (ii) It is the condition of opposing reactions proceeding at the same rate.
The equilibrium constant, Kc, is the ratio of the equilibrium concentrations of products over the equilibrium concentrations of reactants each raised to the power of their stoichiometric coefficients.
Homogeneous equilibria are equilibria in which all reactants and products exist in the same phase. A heterogeneous equilibrium is one in which reactants and products exist in at least two different phases.
Le Châtelier‘s principle states that if a stress is applied to a system at equilibrium, the system will adjust so as to partially relieve the stress.