In a sanitary landfill cH4 (methane) is to be collected as a by-product. Two flows of methane mix adiabatically on a continuous basis. one stream flows at 0.5 kg/min. at 600k with a pressure of 150 kpa and the other flows at 0.8 kg/min. at 300k with a pressureof 120 kpa. The mixing of the two streams continues into a single duct at 110 kpa. Assuming ideal gas behavior, calculate the temperature at the exit methane stream and the entropy change (uses pressures and temperatures) of the methane.