Equilibrium constants K1 and K2 for the following equilibria : NO(g) + (1/2)O2(g) → NO2(g) and 2NO2(g) → 2NO(g) + O2(g) are related as :

To answer this question, we need to understand the relationship between the equilibrium constants K1 and K2 for the given equilibria. The first equilibrium is NO(g) + (1/2)O2(g) → NO2(g), and the second equilibrium is 2NO2(g) → 2NO(g) + O2(g). Notice that the second equilibrium is the reverse of twice the first equilibrium. According to the law of mass action, when an equilibrium is reversed, the equilibrium constant is inverted. Therefore, the relationship between K1 and K2 is K2 = 1/K1. So, the correct answer is option (A) K2 = 1/K1. Think of it this way: when we reverse an equilibrium, the equilibrium constant is inverted, and when we multiply an equilibrium by a factor, the equilibrium constant is raised to that power.