Read our COVID-19 research and news.

American Chemical Society, Reactions

‘Elephant’s toothpaste’ reaction explained in slow motion

It would require a lot of toothpaste for an elephant to brush its teeth, and children across the country are making it by the bottle—sort of. The American Chemical Society’s latest Reactions video breaks down that classic lesson in catalysis, the process of speeding up the rate of a reaction. The slow-motion analysis of the foamy concoction explains how a little mix of detergent and potassium iodide can produce a burst of bubbles when mixed with a 30% hydrogen peroxide solution. (That’s water with an extra oxygen atom.) Hydrogen peroxide is unstable and breaks down over time into water and oxygen gas, but the catalyst potassium iodide speeds up that decomposition into a matter of seconds. Add some soap (and food coloring if you’re feeling adventurous) and you’ve got a mix of soapy water and gas to fill some bubbles. Plenty of fun, but the soapy foam won’t work very well to brush any teeth.

Latest News