"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