Elephant’s toothpaste – so called for its resemblance to toothpaste being squeezed from a tube, on a giant scale, is a fun and showy Chemistry experiment to aid the teaching of ‘catalysts’ and ‘decomposition’.

Hydrogen peroxide breaks down slowly into water and oxygen. Adding a catalyst (in this case, potassium iodide) speeds up this decomposition.

The foamy ‘toothpaste-like’ substance is caused by this very rapid decomposition, as the Oxygen is separated from the Hydrogen peroxide it forms millions of tiny bubbles.

The students were surprised by the sudden appearance of such quantities of coloured foam, overflowing from the containers.

Senior School | 06/05/2021