Elephant Toothpaste

When two liquids are mixed together they produce a lot of foam which looks like toothpaste.

Scientific name: Hydrogen peroxide decomposes and oxygen bubbles produce a lot of foam.


reaction of POTASSIUM IODIDE & HYDROGEN PEROXIDE/ elephant toothpaste

by Basco36

Elephant toothpaste

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Elephant's Toothpaste Geyser With Science Bob on Jimmy Kimmel Live

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Back to School Science Elephant's Toothpaste - Cool Science Experiment

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Chemistry experiment 10 - Elephant's toothpaste

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Elephant Toothpaste

by Nicole Dupuis

Catalytic decomposition of hydrogen peroxide (aka - elephant's toothpaste, Old Foamy)

by ImaginationStationOH


Wear eye protection goggles and lab gloves.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

H2O2 + I- → H2O + IO-

H2O2 + IO- → H2O + O2 + I-

Step-by-step instruction

  1. Prepare a hydrogen peroxide solution, liquid soap, potassium iodide saturated solution, and a bottle or flask.
  2. Mix hydrogen peroxide with liquid soap.
  3. Add the solution of potassium iodide to the hydrogen peroxide/soap mixture.
  4. Hydrogen peroxide decomposes and produces a lot of foam.

Scientific background

This experiment is based on the reaction of hydrogen peroxide decomposition:

2H2O2 → 2H2O + O2

Usually this reaction is very slow. To speed it up the catalyst is added to hydrogen peroxide solution. Potassium iodide participates in the reaction but is not consumed and is recycled:

H2O2 + I- → H2O + IO-

H2O2 + IO- → H2O + O2 + I-

In this case the reaction of hydrogen peroxide decomposition begins and proceeds with high velocity. A lot of oxygen is released and its bubbles cause formation of foam.


Published on 10 March 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst