From a drop of water

An experience. Approximately the same amounts of sodium peroxide Na2O2 and sawdust are mixed on the asbestos board or metal plate. This mixture is given the shape of a branch, its vertex is pressed with a finger and in the pit is started from the pipette 1-2 drops water. The mixture flashes and burns. First, the water reacts with Na2O2 - sodium hydroxide and anhydrous peroxidic hydrogen are obtained:

This mixture is given the shape of a branch, its vertex is pressed with a finger and in the pit is started from the pipette 1-2 drops water

Na2O2 + 22 = 2NaO + 22.

Anhydrous H2O2 is an extremely strong oxidant and produces arson of wood. Then burning is supported by the direct reaction Na2O2 with wood.

An experience. On a dry asbestos mesh, asbestos board or metal plate pour a carefully mixed mixture of aluminum "powder" (1 g) and well-ground iodine (12 g) with a heap. One drop of water is allowed to enter the mixture from the pipette. After a short period of time, a violent reaction occurs - the mixture burns. At the same time, an extra iodine evaporates as a beautiful violet cloud ( experience must be carried out under strong exhaust or in the air). After complete combustion of the mixture on asbestos or metal, there remains a white substance - aluminum iodide. The drop of water in this process plays the role of a catalyst:

2l + 32 = 2l3 + Q.

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