Nevermore
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Concentrating H2O2 by electrolysis
I wish to concentrate my 3% H2O2 up to 15-30% by electrolysis, is that possible or the h2o2 will decompose too?
Thanks
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BASF
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Somewhere in the general chemistry-section is a thread on how to concentrate H2O2.
It is not that difficult. Forget electrolysis. There are better methods.
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Nevermore
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Hello i read all the info on the GC section but they all show vacuum distillation as the most reliable..
and that's not available at me..
i was thinking something easy to concentrate from 3% to 10-15%.
i will try with the evaporation process...
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BASF
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yeah, do that.
Be sure to use clean containers and use a water bath, if you like.
For higher concentrations you can use an exsiccator-like system with a large pot, as described in the mentioned thread.
If you use sulfuric acid, or another strong drying agent, the vacuum is not essentially necessary, although it speeds up the process considerably.
It just takes longer.....
Wish you success
P.S. if you wanna know the conc. you could either measure the density, calculate it from the weight-difference.
60%+ H2O2 ignites flammable matter on contact, 80%+ can even explode....
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Mr. Wizard
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concentrated Hydrogen Peroxide
One of the most painful chemical burns I've ever had was a drop of 30% H2O2 on the skin. It turned white instantly and stung like hell. Washing
it off didn't seem to make any difference. Maybe this belongs in the accidents thread?
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Theoretic
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Concentrating H2O2
Just put your H2O2 in a dish overnight. The water will evaporate, but not the H2O2. You can reach 65% concentration that way.
Edit by Polverone:
And if you split white light into a rainbow with a prism, you can lure leprechauns into glass jars and keep them as pets. I'm just kidding, of
course. Personally (experimentally) verify information you're posting or provide a reference to a reputable source. You
certainly can't concentrate household peroxide to 65% by the method you've provided.
[Edited on 6-20-2003 by Polverone]
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Iv4
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I doubt that it would go that high just leaving out.Just for the hell of it I'll od that next time I get some h202(6%)
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vulture
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Oh yes, you will get 65% water that way! 
Dust will fall into your solution and the peroxide will decompose.
I'm sorry but your talking out of your *ss.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Haggis
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Hey Vulture, if it is 65% water, than 35% H2O2 by evaporation doesn't sound too bad. 
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Iv4
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Just for the hell of it I will still go and do it.Though it will haver to wait till sunday.
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Theoretic
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I tried this method, but ignored the dust - it was a bad mistake. The next morning only dust with a bit of scum was left over in the dish. 
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Theoretic
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A quote from the Internet:
"IF UNCOVERED, THEWATER FROM HYDROGEN PEROXIDE SOLN CAN EVAPORATE, CONCENTRATING THE /REMAINING/ MATERIAL"
This is the closest I could get to the original phrase that prompted me to post in the first place.
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Theoretic
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One could use CaO to concentrate H2O2. Insoluble Ca(OH)2 is left over.
If you really mind a little bit that's dissolved bubble your breath through it. CO2 would make insoluble CaCO3 with the hydroxide.
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blip
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A base such as CaO would cause it to decompose, I've seen it when I tried to make CaO<sub>2</sub> after I mixed a bit of
Ca(OH)<sub>2</sub> with 3% H<sub>2</sub>O<sub>2</sub> (I was using evaporation to get rid of the water).
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Theoretic
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Hey Iv4, did you never proceed with the concentration experiment?
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Theoretic
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Hey Iv4, did you never proceed with the concentration experiment?
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Theoretic
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Aha! Here's the original quote (not from the net, but from a 5-cm thick chemistry book):
"even simple evaporation in an open dish concentrates it to about 60 percent, but beyond this it decomposes"
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Iv4
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Yeah I did as a mter of fact(dont know why).It was 92 fucking percent!WATER...
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Theoretic
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OK, so the core topic of the thread was electrolytic concentration. Well, it's possible, since H2O2 shows very little ionisation in solution
(unlike water).
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