A fuel gas consisting of 94 mol% methane and 6 mol% nitrogen is burned with 35% excess air in a continuous water heater. Both fuel gas and air enter dry at atmospheric temperature. Water is then heated at a rate of 34 kg/s from 25°C to 95°C. The flue gases leave the heater at 210°C. Of the entering methane, 70% burns to carbon dioxide and 30% burns to carbon monoxide. If there are no heat losses to the surroundings, determine the volumetric flow rate of fuel gas is required. Information: Heat of 293.2 kJ/kg is needed to raise the temperature of water in continuous water heater from 25°C to 95°C.