A 7-ft3 rigid tank contains propane at 730 R, 500 lbf/in 2. A valve is opened, and

Question:

A 7-ft3 rigid tank contains propane at 730 R, 500 lbf/in 2. A valve is opened, and propane flows out until half the initial mass has escaped, at which point the valve is closed. During this process the mass remaining inside the tank expands according to the relation Pv1.4 constant. Calculate the heat transfer to the tank during the process.