In a 1 L balloon, we introduce 5 mol of NO, 4 mol of O2, both in the gaseous state. the mixture reacts according to the following equation: 2 NO (g) + O2 (g) = 2 NO2 (g) Once at equilibrium, the amount of O2 in the container is now 2 mol. Determine the equilibrium constant Kc for this reaction