Ammonia can be oxidized in oxygen as shown: 4 NH3(g) + 3 O2(g) <=> 2 N2(g) + 6 H2O(g). When 0.791 mol of NH3 and 0.814 mol of O2 are placed in a 1.00 L container at a certain temperature, the equilibrium [N2] is 0.209. Calculate the value of Kc for the reaction.