3. Texas Barnett Shale gas (well #1) contains 80.3 mol-% methane, 8.1 mol-% ethane, 2.3 mol-% propane, 7.9 mol-% nitrogen, and 1.4 mol-% CO2. (a) What is the standard heat of combustion (kJ.mol-?) of the fuel at 25C with H2O(g) as a product? (b) The fuel is supplied to a furnace with 50% excess air, both entering at 25C. The products leave at 650C. If combustion is complete and if no side reactions occur, how much heat (kJ per mol of fuel) is transferred in the furnace