attrezzo
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Accidentally got a H2O2 burn. Help me figure out why this was so effective.
So I have a CO2 injection system for my fish tank, it consists of a bb-gun type CO2 cartridge connected to a tiny regulator, a bubble counter, and
finally an atomizer stone. When active the line holds pressure at about 30psi and slowly (a bubble a second runs through the bubble counter) pushes
CO2 into the tank.
I must have mixed something up when I set up the bubble counter because I ended up putting H2O2 into it at a 3% store-brand concentration but what
came out was defiantly more like 30%. And I had the white tingling fingers to prove it.
There was some evaporation involved (obviously), my question is at less than 2 ounces of total volume why was the bubble counter so effective at
concentrating the H2O2 in only a few days of use? Does the high pressure have anything to do with it or was it just drying faster from the processed
CO2 running through it.
I'm not a huge chemistry buff so trolls be nice. But I suspect that the combination of dry co2 and pressure kept the H2O2 from decomposing while
evaporating the water quite effectively.
Can you all help me understand what happened here with fancy chemistry terms and all that? I'm one part fascinated that it happened and another part
curious as to how.
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attrezzo
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As an aside, if you needed to concentrate a whole lot of H2O2 and you didn't want to babysit it at a burner for a day. This might be a really FUN way
to do it!
Taking the brewer side of me into account. You could put a good deal of H2O2 into a garden variety soda keg, then bubble co2 in backwards with a high
pressure line and a valve cranked down at the other. Might even do it faster if you could an airstone or something in there.
[Edited on 7-2-2014 by attrezzo]
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bfesser
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Thread Moved
6-2-2014 at 18:06 |
vmelkon
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I don't quite understand it.
You have 3% H2O2 and put it under pressure with CO2? The CO2 would dissolve in it.
You can return it to normal pressure and see if it bubbles like a cola.
3% H2O2 doesn't contain much H2O2. I measured the density and it comes to 1.00 g/cm3. I can't reach higher precision but I'm sure it is very slightly
denser than pure water.
I had 473 mL. I evaporated until I had 50 mL. The density was between 1.07 and 1.08 which I think comes out to 17% H2O2.
THAT is a lot of evaporation.
[Edited on 7-2-2014 by vmelkon]
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Ascaridole
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To say it concentrated the peroxide is premature without any analytical data or observations to back it up a beached finger is a good qualitative
start but titration is the best quantitative analysis.
What might have happened is the carbonic acid formed from the bubbling helped to keep the peroxide solution acidic slowing its decomposition as the
solution evaporated. Another possible explanation is that a peracid was formed.
Ascaridole, the masked bandit of chemistry!
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Galinstan
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sorry to speculate so widely without any evidence but if the CO2 dissolves and forms carbonic acid could it not form peroxycarbonic acid like
carboxylic acid do, which would account for the properties as it would almost certainly be highly oxidizing and corrosive.
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Ascaridole
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Formation of the peroxycarbonic acid is possible and not out of the question. To what extent the peroxy acid actually exists in solution not sure. I'd
stick with the idea that the acidic solution helped to stabilize the hydrogen peroxide while the excess CO2 simply acted as a carrier gas expediting
the evaporation of water.
I still have a bunch of thiosulfate, iodate and iodide solution made up from my weekend iodometry escapade and will try to get some CO2 to replicate
your experiment. Might not be till the weekend but I'll give it a shot.
Ascaridole, the masked bandit of chemistry!
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