Phase Diagrams from Van der Waals Equation of State
The van der Waals equation of state for water is used to generate isotherms on a pressure-log volume (P-V) diagram and isobars on a temperature-log volume (T-V) diagram. Sliders change the isotherm temperature on the P-V diagram and the isobar pressure on the T-V diagram. Liquid and vapor are in equilibrium within the phase envelope, which was generated from data for water. The isotherms and isobars have three solutions in the two-phase region, but the only physically-meaningful conditions are the orange dots, which correspond to saturated liquid and saturated vapor.
This simulation was made at the University of Colorado Boulder, Department of Chemical and Biological Engineering. Authors: Rachael L. Baumann, Patrick Doyle