Equilibrium constant K1 and K2 for the following equilibria (AIPMT 2005) K NO(g) O NO (g) K 2NO (g) 2NO(g) O (g) are related as (a) K K (b) K K (c) K K (d) K K Ans. (d) Sol. Reaction (2) is a reverse reaction of reaction (1) K NO(g) O NO (g) [NO ] K (1) [NO][O ] and the reaction (2) is also twice of the reaction (1). K 2NO (g) 2NO(g) O (g) [NO] [O ] K (2) [NO ] From equa (1), when we square both side, we have [NO ] K [NO] [O ] [NO] [O ] (3) K [NO ] Thus, the equilibrium constant can be given as K = K Hence, the correct answer is option (d)