Sciencemadness Discussion Board

Hydrogen Peroxide simple experiments

Aurus - 20-2-2009 at 13:45

Hey. I have just acquired some hydrogen peroxide and I would like your suggestions on some safe experiments to perform with it.

hellfire23 - 20-2-2009 at 15:56

What percentage?

If its a relatively low one you can get pure oxygen by pouring it over manganese dioxide.

If you have a high percentage, I doubt it, like 90% you can make a type of liquid rocket fuel out of it with the above reaction.

Arrhenius - 20-2-2009 at 23:47

Yep, reaction with MnO2 (or permanganate) is very exothermic producing oxygen and water vapor.

If you pour a little H2O2 in a bottle and add some bleach, it will react less vigorously to give oxygen (stick a lit match near the bottle, it burns quite vigorously).

Also safe would be the reaction of H2O2 with organic dye molecules, destroying the colour.

Measure pH of H2O2 solution, what's going on? Is Peroxide acidic?

H2O2 can react with Na2CO3 to give sodium percarbonate (oxyclean & other bleaching powders). Also reacts with Boric acid B(OH)3 to give borates, which are also used as bleaches.

H2O2 can react with acetic acid to give peroxyacetic acid, which is a useful reagent for converting alkenes to epoxides.

Unsafe would be the formation of organic peroxides, which can probably even be made from 3% peroxide, and are highly sensitive explosives.

Why are organic peroxides explosive, by ionic peroxides such as sodium percarbonate stable?

Aurus - 23-2-2009 at 03:28

Thanks. The concentration of H202 is 6%.

sparkgap - 23-2-2009 at 04:47

"ionic peroxides such as sodium percarbonate stable?"

You haven't seen woelen's little experiment, have you? ;)

This no longer falls under the "safe" requirement of Aurus, though.

sparky (~_~)

(edit: added link)

[Edited on 23-2-2009 by sparkgap]

Arrhenius - 23-2-2009 at 13:55

Lol, no I'll check it out. But yes, generally, ionic peroxides are much more stable. I wouldn't go trying to light them on fire, but organic peroxides are fantastically sensitive by comparison. Put this way: they sell Sodium percarbonate at the store for the layperson to clean their clothes with.

PHILOU Zrealone - 24-2-2009 at 01:34

With conc urea solution and eventually after evaporation at ambiant heat, you get a white addition complex that is of little solubility:
NH2-CO-NH2 + H2O2 --> NH2-CO-NH2.H2O2

After drying in open air it is equivalent to solid 36% H2O2 :)
Beware of it reacting with organics and leading to organic peroxydes! (ex. aceton, ...!)

It is interesting because it allows reaction with much less water than H2O2 36%(*)! But as counterpart you get urea inside the mix...

(*)
MM Urea = 60 g/mol
MM Urea peroxyde = 94 g/mol
MM H2O2 = 34 g/mol
--> 34/94 = 36.17%

P.S.: the stuf is non explosive...it is a stable complex it was in use in a shampoo manufacture where I worked and it was in big drums of 50kg...no specific warning except to avoid mixing it with fuels (reducers) or H2O2 sensitive stufs.

[Edited on 24-2-2009 by PHILOU Zrealone]

[Edited on 25-2-2009 by PHILOU Zrealone]