Interactive Self-Study Module: Immiscible Liquids Phase Diagrams
Department of Chemical and Biological Engineering, University of Colorado Boulder 

This module uses screencasts and interactive simulations to explain the vapor-liquid phase equilibrium of two immiscible liquids. Both pressure-composition and temperature-composition diagrams are explained. It then provides example problems and step-by-step quiz simulations to allow the user to test themselves. We suggest 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 describes the phase diagrams and answer the questions within the screencast.
  3. Use the two interactive simulations to further understand the behavior of the phase diagrams.
  4. Use the quiz interactive simulations to test your understanding by carrying out step-by-step preparation of phase diagrams.
  5. Try to solve the two example problems before watching the solutions in the screencasts.
  6. Answer the ConcepTests.
          Understanding the phase diagrams for immiscible liquids will help in understanding solid-liquid phase diagrams that have multiple solid phases.

This module is intended for a Thermodynamics course and may also be useful for a Materials course.

Before studying this module, you should:

After studying this module, you should be able to:
  1. Construct a pressure-composition diagram at a given temperature for two immiscible liquids, given saturation pressures at that temperature.
  2. Construct a temperature-composition diagram at a given pressure for two immiscible liquids, given Antoine equations (saturation pressure versus temperature) for each component.
  3. Determine what phases are present, given temperature, pressure, saturation pressures, and overall compositions.
  4. Given a vapor composition and saturation pressure data, determine the temperature (at constant pressure) or the pressure (at constant temperature) at which one or more components condenses.