Wikijunior:Big Book of Fun Science Experiments/Explosive foam
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You really need a proper science lab and a trained presenter to do this experiment. It is more of a demonstration than a participatory exercise.
[edit] Ingredients
- a tub which holds about 1 gallon
- water
- soap
- A beaker or test tube
- a stopper with a hole
- glass elbow and rubber tubing
- hydrochloric acid
- magnesium ribbon
- a lighter
[edit] What to do
Step one: fill the tub with very soapy water Step two: fill the beaker or test tube about half way with hydrochloric acid Step three: attach the glass elbow and the hose to the stopper Step four: place the other end of the hose in the tub of soapy water Step five: add a small amount of the magnesium ribbon to the beaker and quickly cover the top with the stopper; hold the beaker so it is lower than the tub and there are no kinks in the hose Step six: bubbles will appear in the tub Step seven: pick up some bubbles with your hand and light them with the lighter; they should go up quite spectacularly without burning your hand Step eight: when you get tired of playing with the bubbles, you can light the ones left in the tub all at once.
[edit] Principle
Magnesium and hydrochloric acid react to create hydrogen gas and magnesium chloride. The chemical equation looks like this:
Mg (s) + 2HCl (aq) --> H2 (g) + MgCl2 (aq)
Because Hydrogen gas is lighter than air, it travels up the tube and bubbles through the water. Hydrogen gas burns at a relatively low temperature and shouldn't harm your hand when you light it.
