56 g of N2 and 6g H2 were kept at 400ºC in l litre vessel. The equilibrium mixture contained 27.54g of NH3. The approximate value of Kc for the above reaction in mol-2 lit2 is

The initial moles of: 2 2 6 H 3mol 2 56 N 2mol 28 2 2 (g ) (g ) N 3H 3 (g ) 2NH initial 2 3 0 at equation 2-x 3-3x 2x At equilibrium, the number of moles of: 3 2 2 27.54 NH 1.62 17 2 1.62 0.81 N 2 2 0.81 1.19 H 3(1 ) 3(1 0.81) 0.57 x x x x The concentration at equilibrium: CHEMICAL EQUILIBRIUM 43 2 2 3 1.19 [N ] 1.19M 1 0.57 [H ] 0.57M 1 1.62 [NH ] 1.62M 1 The value of 2 2 2 c 3 (1.62) K = =11.9mol lit 1.19×(0.57) Hence, the correct answer is 11.9