Dynamic Equilibria

In a closed system a reversible reaction eventually reaches a dynamic equilibrium where

• the rate of forward reaction = the rate of the reverse reaction
• and the concentrations of the reactants and products remain the same.

The Equilibrium Law - (also known as the law of mass action) for the reversible reaction:aA + bB ⇌ cC + dDK_c is the equilibrium constant at a given temperature.The right hand side is called the equilibrium quotient, Q.When a system has reached dynamic equilibrium, Q = K_c.[A] means the concentration of A.If K_c is greater than 10¹⁰ reactions are considered as going to completion. If K_c is less than 10^-10 the reaction is regarded as not taking place at all.