1. The applications of equilibrium constant are:
• To predict the extent of a reaction on the basis of its magnitude.
• To predict the direction of the reaction.
• To calculate equilibrium concentrations.
2. Reaction quotient, Qc at a given temperature is defined as the ratio of the product of concentrations of the reaction products to that of the reactants, each concentration term being raised to their individual stoichiometric coefficients in the balanced chemical equation, where the concentrations are not necessarily equilibrium values.
3. (i) When Qc > Kc , the reaction will proceed in the direction of reactants (reverse reaction), i.e., net reaction goes from right to left.
(ii) When Qc < Kc , the reaction will proceed in the direction of products (forward reaction), i.e., net reaction goes from left to right.
(iii) When Qc = Kc , the reaction mixture will be at equilibrium, i.e., no net reaction occurs.