Elephant Toothpaste Demo

I mentioned how to perform a kid-friendly version of the elephant toothpaste demo, but I didn't tell you how to perform the classic demonstration. I've added instructions for that demo. This is a memorable demonstration because it produces an astounding amount of hot foam. If you run a stripe of food coloring down the side of your container, you can get foam that sort of resembles Aquafresh™ toothpaste. Another option for the demonstration is to perform it using a 2-liter plastic bottle. The heat from the reaction will shrink the bottle from its original size. This is readily apparent if you have another 2-liter bottle available for comparison.

If you have access to 30% hydrogen peroxide, by all means try the original demonstration. Be sure to wear gloves and eye protection since peroxide is reactive. You can substitute sodium iodide for the potassium iodide. If you don't want to prepare a saturated potassium iodide solution, solid potassium iodide may be substituted. The reaction will proceed a bit more slowly if you use the solid catalyst.