Problem 2.1 (closed system) a piston-cylinder device contains 25 g of saturated water vapor that is maintained at a constant pressure of 300 kpa. a resistance heater within the cylinder is turned on and passes a current i) of 0.2 a for 5 min for a 120 v source. at the same time, a heat loss of 3.7 kj occurs. determine the final temperature of the steam.