School Science/Cannon fire

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 which increases the rate of burning of the ethanol.

Safety

Wear eye protection / full face shield
Remove any concentrated sulfuric acid from the area when using potassium manganate(VII)
Avoid inhaling any vapour produced
Be aware of the pale blue / invisible flame that is produced by the burning ethanol

Required

Heatproof surface
Large evaporating basin or metal plate
Safety screens
Splints
Hydrogen peroxide (20%)
0.5 g potassium manganate(VII)
Ethanol

Method

Place 30 cm³ hydrogen peroxide and 20 cm³ 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

Notes

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

It's worth while covering the benches with heatproof mats or such like, this one can go off. I love it!