Interactive Self-Study Module: Chemical Potential
Department of Chemical and Biological Engineering, University of Colorado Boulder 

This module uses screencasts and an interactive simulation to explain chemical potential for pure components and mixtures. It then provides example problems 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 three screencasts that describe chemical potential and answer the questions within the screencasts.
  3. Use the interactive simulation to further understand the behavior of phase equilibrium.
  4. Try to solve the example problem before watching the solution in the screencast.
  5. Answer the ConcepTests.

Chemical potential helps predict the thermodynamic equilibrium of a system.

This module is intended for a thermodynamics course.

Before studying this module, you should:

  • Be familiar with Gibbs-free energy, entropy and enthalpy.
  • Understand partial derivatives.
  • Know what the triple point is for a single component and be able to locate it on a phase diagram.
  • Be able to apply the Gibbs phase rule.
  • Be familiar with partial molar properties.

After studying this module, you should be able to:
  1. Explain what chemical potential is.
  2. Determine which phase is more stable, given plots of chemical potentials versus temperature or pressure for a pure component.
  3. Explain, using chemical potential, why adding salt to water lowers its melting point and raises its boiling point.
  4. Explain why increasing the pressure melts ice, but increasing the pressure makes solid ethanol more stable.