Liquid octane (C8H18) at 77F, 1 atm enters a combustion chamber operating at steady state and burns completely with 50% excess dry air entering at 120F, 1 atm. The products exit at 1060F, 1 atm. Determine the rate of heat transfer between combustion chamber and its surroundings in Btu per lbmol of fuel entering. Kinetic and potential energy effects are negligible