The heat capacity is a function of pressure also (for non-ideal gas behavior). You really need to include the effect of pressure on gas enthalpy.Yes I actually started Denbigh yesterday and it seems to have similar stuff, so I might continue with this (the effect of composition on liquid heat capacity, deviation from Raoults law). Is this reasonable?
The latter, just the ideal gas heat capacity (function of temperature only). I think I can check the variation of liquid heat capacity with temperature for a given pressure, though.
So the plan is loosely to tackle the non ideality of the vapour and liquid phases? And yes I agree that this will require textbook reading on my part, for me to be able to discuss this (two days or so of reading)