Genie in a Bottle

2 liter soda bottle (or other container -beaker, flask, etc), goggles, spatula, mortar and pestle

30% hydrogen peroxide, manganese dioxide, it's catalytic effect is greatest if it is freshly ground within 24 hours of use.

1. Pour 50-100 mL of 30% hydrogen peroxide into 2 liter bottle (enough to cover the "dimples") or container.
2. Add a pea-sized amount of manganese dioxide to bottle or container.
3. Gaseous oxygen will be emitted from the bottle. The reaction is exothermic; the soda bottle will get hot and shrink slightly.

30% hydrogen peroxide is a strong oxidizing agent; contact with eyes and skin should be avoided. In case of contact, flush with water for at least 15 minutes. Get medical attention if eyes are affected. Also avoid contact of hydrogen peroxide and combustible materials. 30% hydrogen peroxide must be stored in its original container.

Oxygen is a colorless, odorless gas at room temperature and atmospheric pressure. The discovery of oxygen is typically attributed to Joseph Priestly. However, it was Lavoisier who first realized this gas was a unique component of air. Here oxygen is formed from the decomposition of hydrogen peroxide. Hydrogen peroxide is not a very stable compound and its decomposition can be induced by many means. Light will decompose it, which is why it is sold in brown bottles in drugstores. The surface of manganese dioxide provides a particularly favorable environment to catalyze the decomposition, though the mechansim is somewhat poorly understood.

2 H₂O_{2 (aq)} O_{2 (g)} + 2 H₂O_(l)

The "genie in the bottle" effect is finely divided water droplets propelled from the bottle by the oxygen formed via the decomposition of hydrogen peroxide.

1. B. Z. Shakhashiri, Chemical Demonstrations, A Handbook for Teachers of Chemistry, Wisconsin, 1989, Vol.2, p.137-141