Interactive Self-Study Module: Phase Diagrams of Partially-Miscible Liquids

This module uses screencasts and interactive simulations to explain the vapor-liquid phase equilibrium of two liquids that partially miscible in the liquid phase. Both pressure-composition and temperature-composition diagrams are explained. It then provides example problems to allow the user to test themselves. We suggest reviewing the Vapor-Liquid Equilibrium for Non Ideal Solutions Module before using the learning resources in the following order:

    1. Attempt to answer the multiple choice ConcepTests before watching the screencasts or working with the simulations.
    2. Watch the screencast that describe the phase diagrams and answer the questions within the screencast.
    3. Use the interactive simulations to further understand the behavior of the phase diagrams.
    4. Try to solve the two example problems before watching the solutions in the screencasts.
    5. Answer the ConcepTests.


    Partial miscibility can be important in some separations.

    This module is intended for a thermodynamics course and separations course.


    • Be able to use single-component phase diagrams.
    • Know how to determine fugacity and activity for a component in a mixture.

    After studying this module, you should be able to: