Explosion in the box

We prepared:

• a stand
• 2 empty plastic boxes; smaller and bigger so that one could be a kind of lid to the other
• a small piece ( ball) of calcium carbid ( not wet or old)
• water in the wash bottle
• matches

We made a little hole in the bottom of the bigger box. Then a piece of carbide was put in the box in such way so that the hole was higher ang water could be added on the carbide ball.
Carbide reacts with water and in the reaction we obtain a gas - acetylene C2H2:

CaC2 + 2 H2O = C2H2 + Ca(OH)2

Acetylene is flammable and it burns silently if it's pure. When it is mixed with air , explodes and throws away the upper box.



http://www.youtube.com/watch?v=A9QvpGiNgQw