2. Water initially at 155°C is contained in a piston-

cylinder assembly. The water undergoes a process to

the corresponding saturated vapor state, during which

the piston moves freely in the cylinder. There is no

heat transfer with the surroundings. If the change of

state is brought about by the action of a paddle wheel,

determine the net work per unit mass in kJ/kg and the

amount of entropy produced per unit mass in kJ/kg.

[MO2]