Saturated water vapor is contained in a rigid container. heat is then added until the the pressure and temperature become 156.1 kpa and 400c, respectively. what was the initial temperature of the steam?

Avolume of 2.65 m3 of air in a rigid, insulated container fitted with a paddle wheel is initially at 264 k, 5.6 bar. the air receives 432 kj by work from the paddle wheel. assuming the ideal gas model with cv = 0.71 kj/kg • k, determine for the air the amount of entropy produced, in kj/k