One kilogram of water is contained in a piston-cylinder device at 100 °c. the piston rests on lower stops such that the volume occupied by the water is 0.835 m. the cylinder is fitted with an upper set of stops. when the piston rests against the upper stops, the volume enclosed by the piston-cylinder device is 0.841 m3. a pressure of 200 kpa is required to support the piston. heat is added to the water until the water exists as a saturated vapor. how much work does the water do on the piston? what is the heat transfer?