Introduction to Equilibrium Thermodynamics: Salt Dissolution

Andrew Knudsen
,
Lawrence University


Summary

Students dissolve simple salts, halite and sylvite, in water at different temperatures and explore the thermodynamics of this simple system to build a foundation for further studies.

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Context

Audience

Undergraduate low-temperature geochemistry course

Skills and concepts that students must have mastered

none

How the activity is situated in the course

This is the lab I run in the first week of my low-temperature geochemistry course.

Goals

Content/concepts goals for this activity

Students simply dissolve salt in water. The goal of this exercise is to take the intimidating concept of equilibrium thermodynamics and make it as simple as possible.

Students also practice some basic lab skills, mixing solutions, using a balance and a hot plate, etc. that they will come back to later in the term.

Higher order thinking skills goals for this activity

data and error analysis

Other skills goals for this activity

Description of the activity/assignment

In this lab I simply have students dissolve halite and sylvite in water at various temperatures. I use this experiment to introduce students to the principles of equilibrium thermodynamics, as well as basic lab skills, data analysis, and lab report writing. Students use basic laboratory skills to conduct their experiments then analyze their data using a spreadsheet program such as Excel. They then write up their results and discussion in a formal lab report.

Determining whether students have met the goals

To evaluate this exercise I grade students formal lab reports.

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Teaching materials and tips

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