The radiator of a steam heating system has a volume of 32 l and is filled with superheated water vapor at 200 kpa and 150°c. at this moment both the inlet and the exit valves to the radiator are closed. after a while the temperature of the steam drops to 40°c as a result of heat transfer to the room air. determine the entropy change of the steam during this process. (round the final answer to three decimal plac