Dynamic Equilibrium Text

Dynamic equilibrium

  • Chemical reactions can attain a state of equilibrium where the rates of forward and reverse reactions become equal, resulting in constant concentrations of reactants and products.
  • Equilibrium is dynamic in nature and involves a forward reaction in which reactants form products and a reverse reaction in which products form reactants.
  • Chemical equilibrium can be demonstrated using the reversible reaction A + B ↔ C + D.
  • The composition of a reaction mixture remains constant at equilibrium even though some reactants may still be present.
  • The dynamic nature of equilibrium can be demonstrated in the synthesis of ammonia by Haber’s process.
  • Scrambling of H and D atoms in the molecules in the mixture of H2, N2, NH3 and D2, N2, ND3 is the result of the continuation of forward and reverse reactions even after equilibrium is attained.

  • Chemical reactions reach a state of dynamic equilibrium in which the rates of forward and reverse reactions are equal and there is no net change in composition.
  • Equilibrium can be attained from both sides of the reaction.
  • The reaction between H2(g) and I2(g) to form 2HI(g) can be started with equal initial concentration of H2 and I2, leading to a decrease in the concentration of H2 and I2 and an increase in the concentration of HI until equilibrium is reached.
  • The reaction can also be started with HI alone and made to proceed in the reverse direction, leading to a decrease in the concentration of HI and an increase in the concentration of H2 and I2 until equilibrium is reached.
  • If the total number of H and I atoms are the same in a given volume, the same equilibrium mixture is obtained whether starting from pure reactants or pure products.