Nitrogen is stored in a tank at a pressure of 20 bar and 300 k. the tank has a capacity of 2.0 m3. gas is allowed to escape through a partially opened valve until the pressure reaches 2 bar. treat nitrogen gas as an ideal gas with a constant heat capacity of cp = 29.3 j/(mol k). consider two di erent assumptions about the relative rates of mass and heat exchange: (a) adiabatic: the process occurs suciently rapidly that there is negligible heat ow between the gas in the tank and its surroundings. (b) isothermal: gas leaks out of the tank so slowly that the temperature in the tank remains at 300 throughout the process, due to heat exchange with the surroundings.