The composition of a gas derived by the gasification of coal is by volume percentage: carbon dioxide 4, carbon monoxide 16, hydrogen 50, methane 15, ethane 3, benzene 2, balance nitrogen. If the gas is burned in a furnace with 20% excess air, calculate.

i. The amount of air required per 100 kmol of gas; 

ii. The amount of flue gas produced per 100 kmol of gas; 

iii. The composition of the flue gases, on a dry basis. Assume complete combustion.