Warning 30% hydrogen peroxide can burn your skin. Adult supervision required. The bottle will get very hot.
The genie in a bottle demonstration shows a decomposition reaction. A decomposition reaction is when a substance is broken up into two or more different substances. In this case, hydrogen peroxide, whose molecular formula is H202, is being broken down into oxygen and water. Hydrogen peroxide is easily decomposed by light and that is why they are sold in brown bottles in drugstores.
To speed up the reaction, the compound manganese dioxide is being used as the catalyst. A catalyst provides an alternative way for the reaction that has a lower activation energy and its used to speed up the length of chemical reaction.
This experiment also demonstrates an exothermic reaction which means when the hydrogen peroxide decomposes it also releases heat. Therefore, the bottle will be very hot after the reaction.
1. Pour 50-100 mL of 30% hydrogen peroxide into a bottle with a funnel, just enough to cover the “dimples”.
2. Add a pea-sized amount of manganese dioxide to bottle. I wrap it in a tissue and tape thread and hang it just above the hydrogen peroxide.
3. If your thumb holds the thread when you open the top it will not cause a reaction, but when you let go of the thread the manganese dioxide will fall into the hydrogen peroxide and cause the reaction.
3. Stand back as the gaseous oxygen will be emitted from the bottle.