In a test of a gas-turbine combustor, saturated liquid methane at 115 K is burned with excess air to hold the adiabatic flame temperature to 1600 K. It is assumed that the products consist of a mixture of CO₂, H₂0, N₂, 0₂' and N_O in chemical equilibrium. Determine the percent excess air used in the combustion, and the percentage of N_O in the products.