LearnChemE

Equations of State: Interactive Simulations

These simulations run in your browser.  Try to predict the behavior when a parameter changes before using a slider to change that parameter. Screencasts below explain how to use these simulations. The first simulation has a screencast to explain how to use it.

Simulation: Phase Diagrams from van der Waals Equation of State

Try to answer these questions before determining the answer with the simulation. We suggest that you write down the reasons for your answers.

  1. For the critical isotherm obtained from the van der Waals equation of state, what can you say about the slope of the isotherm at the critical point?
  2. Do isotherms generated by a cubic equation of state have three solutions for temperatures below the critical temperature?
Simulation: Compressibility Factor Charts (optional)

Try to answer these questions before determining the answer with the simulation. We suggest that you write down the reasons for your answers.

  1. If the compressibility factor for carbon dioxide is 0.52 at a reduced pressure of 1.59 and a reduced temperature of 1.10, what reduced temperature would you expect for nitrogen to have a compressibility factor of 0.52?
  2. Why is the compressibility factor mostly less than one?