Interactive Self-Study Module: Chemical Potential
Overview:
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. Your retention of material in this module will increase if you write down reasons for your answers to ConcepTests, questions in screencasts, and questions to answer before using the interactive simulation, and you try to solve the example problems before watching the screencast solutions. We suggest using the learning resources in the following order:
- Attempt to answer the multiple-choice ConcepTest and solve the example problem before watching the screencasts or working with the simulations.
- Watch the screencasts that describe chemical potential and answer the questions within the screencasts.
- Review important equations.
- Use the interactive simulation to further understand the behavior of phase equilibrium.
- Use the quiz interactive simulation to understand chemical potential plots.
- Try to solve the example problems before watching the solutions in the screencasts.
- Answer the ConcepTests.
- Look at the list of key points, but only after you try to list the key points yourself.
Motivation:
- 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:
- Explain what chemical potential is.
- Determine which phase is more stable, given plots of chemical potentials versus temperature or pressure for a pure component.
- Explain, using chemical potential, why adding salt to water lowers its melting point and raises its boiling point.
- Explain why increasing the pressure melts ice, but increasing the pressure makes solid ethanol more stable.