"Shaving foam"

Decomposition of H2O2 :

To carry that experiment you need:

• high buret
• 30% hydrogen peroxide (perhydrol)
• solid potassium or sodium iodide ( KI or NaI)
• soap powder

BE CAREFUL! 30% HYDROGEN PEROXIDE IS VERY CORROSIVE!

Pour perhydrol into the buret (about 1/5 of its height), then pour the soap powder -
about 1 teaspoonful. Mix the soap with the liquid.

After that add 1/2 of teaspoonful of solid potassium iodide. Be carefull because foam appears very quickly and it could make some brown stain - it contains iodine I2 .

3H2O2 + KI = 3H2O + KIO + O2

2KIO + H2O2 = I2 + 2KOH + O2

Oxygen causes a lot of foam if soap is mixed with perhydrol before adding KI.


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

The balloon that doesn't explode

A balloon full of water can be burned for a long while by a burner without exploding.

Barbeque balloon

This is an experiment where we can see that vegetable oil may create a membrane that prevents a balloon from exploding.

Potassium and water

This video is about the reaction of potassium and water.

Effusive Volcano

An experiment with balsamic vinegar and baking powder to produce an effusive volcano.

The Fire Extinguisher

By David Arez
Escola Secundária de Loulé Portugal

This is movie about the functioning of carbon dioxide fire extinguishers.
If oxygen is removed by a gas that isn't combustive then the combustion reaction comes to an end.

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

Fire without matches

We carried out the experiment wich shows how to make a fire without matches.

We used potassium permanganate KMnO4 and glycerine C3H5(OH)3.

Be careful and wait while doing it, fire appears after several seconds.

http://www.youtube.com/watch?v=kpae8Xh90mI