Cannon fire is an audio experiment that produces a series of crackles and bangs like gunfire. The noises are produced by hydrogen peroxide and potassium manganate(VII) reacting to produce oxygen. These increase with the rate of burning of the ethanol.

Table of contents
1 Safety
2 Required
3 Method
4 Notes



  • Heatproof surface
  • Large evaporating basin or tin plate
  • Safety screens
  • Splints
  • 20 vol hydrogen peroxide
  • 0.5 g potassium manganate(VII)
  • Ethanol


  1. Place 30cm3 hydrogen peroxide and 20cm3 ethanol into the basin
  2. Surround the basin with screens and light the mixture with the splint. The ethanol will burn with a pale blue or invisible flame
  3. Sprinkle 0.5 g of potassium manganate(VII) into the dish


  • A fine powdered potassium manganate(VII) will give lots of bangs that are fairly quiet. Course powdered potassium manganate(VII) however, will give fewer, louder bangs.