This 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.
- Wear eye protection / full face shield
- Remove any concentrated sulphuric acid from the area when using potassium manganate(VII)
- Avoid inhaling any vapour produced
- Be aware of the pale blue / invisble flame that is produced by the burning ethanol
- Heatproof surface
- Large evaporating basin[?] or tin plate
- Safety screens
- Splints
- 20 vol hydrogen peroxide
- 0.5 g potassium manganate(VII)
- Ethanol
- Place 30cm3 hydrogen peroxide and 20cm3 ethanol into the basin
- Surround the basin with screens and light the mixture with the splint. The ethanol will burn with a pale blue or invisible flame
- 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.