The numerical value of the equilibrium constant for a particular reaction is constant as long as the temperature is kept constant.
The rate of a chemical reaction increases with increase in temperature. The extent of this increase in rate depends upon the energy of activation of the reaction.
Since the energy of activation for the forward and backward reaction are different so a given increase in temperature will increase the rate of forward and backward reaction to different extends.
The values of the velocity constant for forward and backward reaction will change differently with a given rise or fall in temperature.
Since K= kf /kb therefore, the value of equilibrium constant will change i.e. the state of equilibrium is altered.
The value of equilibrium constant of an endothermic reaction increases and that of an exothermic reaction decreases with rise in temperature.
For reaction having zero heat of reaction, the temperature has on effects the value of K.