Propane (c3h8) at 298 k, 1 atm, enters a combustion chamber operating at steady state with a molar flow rate of 0.7 kmol/s and burns completely with 200% of theoretical air entering at 298 k, 1 atm. kinetic and potential energy effects are negligible. if the combustion products exit at 560 k, 1 atm, determine the rate of heat transfer for the combustion chamber, in kw. repeat for an exit temperature of 298 k.