Sciencemadness Discussion Board

Leeching H2O2 from sodium percarbonate.

White Yeti - 17-12-2011 at 20:00

I've been thinking about experimenting with peracetic acid and explore its properties, but in order to make some, I need large amounts of fairly concentrated H2O2.

So, I was wondering how could I separate the hydrogen peroxide from the sodium carbonate in sodium percarbonate and subsequently react it with glacial acetic acid and H2SO4 to make appreciable amounts of peracetic acid.

Adas - 18-12-2011 at 00:43

You can't get H2O2 from sodium percarbonate, because it spontaneously decomposes (Na2CO3 is basic). You can use 3% H2O2 and distill it at lower pressure, or you can evaporate the water, but this takes too much time.

hissingnoise - 18-12-2011 at 08:01

Quote:
You can use 3% H2O2 and distill it at lower pressure, or you can evaporate the water, but this takes too much time.

Much easier to buy 35% on ebay - prices have shot up steeply of late, I notice though.


White Yeti - 18-12-2011 at 08:26

Quote: Originally posted by hissingnoise  
Much easier to buy 35% on ebay - prices have shot up steeply of late, I notice though.


So, 35% would do the trick for this kind of synthesis? I've tried concentrating 3% before up to what I think is about 10% concentration. Would that do the trick as well? I'd rather distil the 3% than buy some 35% at the moment.

Bot0nist - 18-12-2011 at 12:52

If all you need is 10% it is really simple to get it from 3%. Check the search engine. Even without the ability to distill under reduced pressure the highly available and cheap 3% H<sub>2</sub>O<sub>2</sub> can be concentrated with minimal effort and equipment, IMO.

Here's two.

http://www.sciencemadness.org/talk/viewthread.php?tid=15881
http://www.sciencemadness.org/talk/viewthread.php?tid=16726

[Edited on 18-12-2011 by Bot0nist]

White Yeti - 18-12-2011 at 14:06

Quote: Originally posted by Bot0nist  
If all you need is 10% it is really simple to get it from 3%. Check the search engine. Even without the ability to distill under reduced pressure the highly available and cheap 3% H<sub>2</sub>O<sub>2</sub> can be concentrated with minimal effort and equipment, IMO.


That's the thing, I don't know how concentrated the peroxide has to be in order for this synthesis to work well. Theoretically, 3% would work, but my product would be incredibly dilute. I wish I could get 35%, but I don't have access to it at the moment. All I have is sodium percarbonate and 3% H2O2.

hissingnoise - 18-12-2011 at 14:37

Quote:
I wish I could get 35%, but I don't have access to it at the moment.

http://www.ebay.co.uk/itm/500ml-Hydrogen-Peroxide-35-Technic...