Liquid petroleum gas (LPG) is used to fuel spark-ignition engines. A typical sample of the fuel consists of:

70 percent by volume propane ...................C3H8

5 percent by volume butane .....................C4H10

25 percent by volume propene ..................C3H6

The higher heating values of the fuels are: propane, 50.38 MJ/kg; butane, 49.56 MJ/kg; propylene (propene), 48.95 MJ/kg.

(a) Work out the overall combustion reaction for stoich. combustion of 1 mole of LPG with air, and the stoichiometric F/A and A/F.

(b) What are the higher and lower heating values for combustion of this fuel with excess air, per unit mass of LPG?