Methane gas is burned entirely with 20% excess air at approximately atmospheric pressure. Both the methane as well as the air enter the furnace at 30°C saturated with water vapor and the flue gases leave the furnace at 1500°C. The flue gases after that pass through a heat exchanger from which they emerge at 50°C. Per mole of methane, explain how much heat is lost from the furnace and how much heat is transferred in the heat exchanger?