$2HI\left(g\right)\rightleftharpoons H_2\left(g\right)+I_2\left(g\right)$

The equilibrium constant of the above reaction is 6.4 at 300 K. If 0.25 mole each of H₂ and I₂ are added to the system, the equilibrium constant will be:

The value of equilibrium constant is temperature dependent. Its value is independent of the concentration of reactants. Thus, when concentrations of H₂ and I₂ are increased, the equilibrium constant will remain same as given, i.e., 6.4.