Chemical Activities Involving Reversible Thermochromic Pigments

The color of a thermochromic system depends on its temperature. The colors of leuco dye-based systems can also be influenced by adding acids or bases to the thermochromic reactions. These can be used to create colorful demonstrations of acid-base chemistry. Thermochromism found in color changing cups can also be used to visualize heat flow, and therefore thermodynamic principles, associated with stretching and contracting elastomers.

Seashell Chemistry

Placing dry ice in limewater is a great demonstration to accompany discussions on a variety of chemical topics, including the impact of ocean acidification on marine organisms that depend upon the formation of CaCO3.

Upgrading a Classic Science Demonstration

In a classic demonstration of energy conservation, smashing two large steel ball bearings generates sufficient heat to burn a hole through a piece of paper. Josh Kenney found this demonstration underwhelming because the paper doesn't look burned. So, he upgraded the experiment by covering the paper in Elmer's Color Changing Glue. Now, a spectacular color change reveals the increase in heat!

Gibbs Free Energy Analogy

A common topic in chemistry discussion groups and forums is about the use of the terms “spontaneous reaction” versus “thermodynamic favorability”. This is a new activity for chemistry students who struggle with the correlation between changes in enthalpy, temperature, entropy, and the Gibbs free energy of a system; which relies on an analogy that most students will be familiar with.