Problem 14.16:A major air pollution problem in combustion is the formation of NO from the reaction between O2 and N2 :
N2 + O2 = 2NO.

a) Calculate the equilibrium constant and the heat of reaction at 25 °C for this reaction. Is the reaction exothermic, or endothermic?

b) Determine the effect of pressure and temperature on the amount of NO formed from this reaction. Explain your answer.

c) A high-temperature furnace operates at 5 bar with temperatures in the range 1,000 to 2,000 K by burning methane in 20% excess air. You are concerned that the air in the furnace may produce unacceptable amounts NO. By regulation, the concentration of NO in the gases leaving the furnace may not exceed 500 ppm by mole. At what temperatures can you operate the furnace without violating the regulation?

Note: A concentration of 1 ppm (parts per million) corresponds to mole fraction of 10-6. You may assume that the heat of reaction is independent of temperature