1) 2)3) 4) From the above data, the most stable oxide is

2.2 x 10-334.54 x 1032 → (2)3.8 x 10-322.63 x 1031 → (3) All the above reactions indicate formation of oxides of nitrogen.Greater the KC value for the formation of oxide, greater the thermodynamic stability of the oxide.Thermal stability of NO > N2O5 > NO2 > N2O