Confusion with the PR EOS

[mmckendry]

I am trying to calculate the pressure of a mainly two component mixture (propane/butane). I have an estimated composition and I want to calculate the pressure based on this estimated composition and see how it matches up to physically measured pressure. My problem is that I don't understand how I am supposed to find molar volume without knowing density which is a function of pressure. Second, will the form I posted of the PR EOS work if I input a molar volume of my mixture in the liquid phase? I have not gotten reliable results with that so far. Lastly, how do I finding overall V? currently I am calculating it like this x[sub]i[/sub]M[sub]i[/sub]/p[sub]avg[/sub].

Thanks for any help.

 

[Latexman]

Patrick Barrie's thermodynamics teaching page may help. Predicting vapour-liquid equilibrium of binary mixtures using cubic equations of state.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.