Elephant's Toothpaste Used as a Qualitative Demonstration of Rate versus Temperature

Ben Ruekberg, University of Rhode Island
David L. Freeman, University of Rhode Island


The popular elephant's toothpaste demonstration can be used to demonstrate the effect of temperature on reaction rate qualitatively. Our version is designed for simplicity of execution and to require little class time. Two runs of the reaction are performed at easily achieved temperatures (ice and ambient), the latter being approximately three times as fast. The reaction behind the demonstration, the iodide-catalyzed decomposition of hydrogen peroxide (along with some complicating side-reactions), is discussed in some detail.