Intro

Add soap to conc. Hydrogen peroxide, then add a decomposition catalyst (MnO2 or KI). The hydrogen peroxide decomposes to water and oxygen gas very quickly releasing a stream of soapy bubbles that looks like toothpaste. Can add food colouring to give colourful toothpaste

Equipment

• 100 or 50 ml graduated cylinder
• Spatula
• Gloves
• Something to set-up on (table)
• Empty pop bottle
• Mop and/or paper towels to clean up after each run

Materials

• H2O2 (at least 30% conc.)
• KI powder or MnO2 (or both)
• Liquid Soap (large bottle)
• Optional food colouring

Background Science

Considerations:

• Hydrogen peroxide is pretty toxic, but low chance of exposure
• Reaction is quite exothermic, and reaction vessel could explode if stoppered or closed
• Gets messy and has chemical vapors, so preferably outdoors
• Only really needs a table to set-up on