A Gas boiler burns natural gas with the volumetric analysis as follows: CH4 = 85% ; C2H6 =12% ; C3H8 = 3%. The Fuel flow rate is .40 m^3/sec and 25% excess air is required for complete combustion. Fuel and air are at 298 K and 100 KPa and product temperature is 800 K at 100 KPa. Determine:

a. The moles of O2 and N2 in the products

b.The actual A/F ratio in kg/kg

C. The m^3/sec of combustion air

D. The Lower Heating Value (LHV) of the fuel in KJ/kg is nearest to

E. The molecular weight of the fuel mixture is nearest to