Two moles of HI were heated in a sealed tube at 440ºC till the equilibrium was reached. HI was found to be 22% decomposed. The equilibrium constant for dissociation is

2 2 2 H I H + I -> 2 0 0 Initial (2 2 ) x x x equilibrium c d c a b 2 2 2 2 c 2 For reaction, aA bB cC dD [C] [D] K [A] [B] For reaction, 2HI H + I [H ][I ] K [HI] 2 c 2 2 (0.22) K = (2 2 ) 4 (0.78) x x x x x =0.0198 KP = Kc = 0.0198 Hence, the correct answer is 0.198