A vertical cylinder is fitted with a piston held in place by a pin. The initial volume is 200 L and the cylinder contains moist air at 100 kPa, 25C, with wet-bulb temperature of 15C. The pin is removed, and at the same time a valve on the bottom of the cylinder is opened, allowing the mixture to flow out. A cylinder pressure of 150 kPa is required to balance the piston. The valve is closed when the cylinder volume reaches 100 L, at which point the temperature is that of the surroundings, 15C.
a. Is there any liquid water in the cylinder at the final state?
b. Calculate the heat transfer to the cylinder during the process.
c. Take a control volume around the cylinder calculate the entropy change of the control volume and that of the surroundings.