chemistry experiments - the wax flamethrower

This has to be one of the best loved show experiment amongst Flensburg’s chemistry students:
The wax flame thrower!

Since the experiment has found its way into the Flensburg laboratories, it has been shown at a number of events to great acclaim from the audience. This experiment is a relatively safe way to demonstrate combustion. It can also be used in fire safety education. If you try to extinguish burning fat or the wax on the Christmas decorations with water, you get the same effect. This is a serious risk, as your intuition will always tell you to use water to put out a fire. But in these cases, that would be the worst thing to do – as this experiment demonstrates.
The combustion you can see so clearly in the video comes about through a number of steps.
1. The test tube is around 400° C hot; exposed to the cold water, it cools down rapidly and the bottom of the tube shatters.

2. Through the hole thus caused, water enters the test tube and meets the hot wax.

3. The water in the test tube evaporates immediately, greatly expands in volume and drives the liquid wax upwards and outwards.

4. The liquid wax and further gaseous components are ejected from the tube and finely disseminated.

5. The heat, fine dissemination and consequent high saturation with Oxygen mean that small, cracked particles (Hydrogen radicals) ignite in the waxen steam.

6. The flame of the radical reaction ignites the liquid part of the wax mixture.

So, there is also a lot going on chemically with this experiment.
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