A gaseous fuel containing methane and ethane is burned with excess air. The fuel enters the furnace at 25 C and 1 atm, and the air enters at 200 C and 1 atm. The stack gas leaves the furnace at 800 C and 1 atm and contains 5.32 mole% CO2, 1.60% CO, 7.32% O2, 12.24% H₂O, and the balance nitrogen. Calculate the heat (k]) transferred from the reactor per cubic meter of fuel gas fed.