Natural gas composed of 60. mol% methane, 30. mol% ethane, and 10. mol% propane at 25 °C and 500. psia is fed at a rate of 50. m3/hr into a boiler. In the boiler it is blended with enough air to provide 20% excess oxygen and combusted. The exhaust gas is passed through several air pollution control unit operations before being released through a smokestack into the atmosphere at a temperature of 400 °C. Determine the flow rate (in m3/hr) of exhaust gas through the smokestack.