Before considering the applications of equilibrium constants, let us summarise the important features of equilibrium constants as follows:

Expression for equilibrium constant is applicable only when concentrations of the reactants and products have attained constant value at equilibrium state.

The value of equilibrium constant is independent of initial concentrations of the reactants and products

Equilibrium constant is temperature dependent having one unique value for a particular reaction represented by a balanced equation at a given temperature

The equilibrium constant for the reverse reaction is equal to the inverse of the equilibrium constant for the forward reaction.

The equilibrium constant K for a reaction is related to the equilibrium constant of the corresponding reaction, whose equation is obtained by multiplying or dividing the equation for the original reaction by a small integer

Let us consider applications of equilibrium constant to:

predict the extent of a reaction on the basis of its magnitude,

predict the direction of the reaction, and

calculate equilibrium concentrations.