(I) 1. The value of equilibrium constant KC tells us the extent of the reaction i.e., it indicate how far the reaction has proceeded towards product formation at a given temperature.
2. A large value of KC indicates that the reaction reaches equilibrium with high product yield on the other hand, lower value of KC indicates that the reaction reaches equilibrium with low product yield.
3. If K > 10-3 , the reaction proceeds nearly to completion.
4. If KC < 10-3 the reaction rarely proceeds.
5. It the KC is in the range 10-3 to 103, significant amount of both reactants and products are present at equilibrium.
(II) Addition of catalyst does not affect the state of equilibrium. The catalyst increases the rate of both the forward and reverse reactions to the same extent. Hence it does not change the equilibrium composition of the reaction mixture.