1. The problem statement, all variables and given/known data Calculate the mass of water contained in a 0.6 ft^3 vessel under the following conditions: a) 15 psia, 300 F b) 100 psia, 500 F c) 20 psia, 210 F d) 60 psia, saturated vapor e) 60 psia, saturated liquid f) at the critical state 2. Relevant equations PV=mRT 3. The attempt at a solution I suppose the ideal gas equation is valid? Can someone explain to me why or why not? Assuming it's valid, for a,b the temperature is above the saturation (boiling) temperature, so R would be the water gas constant? For c, d, e, and f, I don't know what values to plug in for R. Any help would be appreciated. Thanks.