kt5000
Hazard to Others
Posts: 133
Registered: 27-3-2013
Location: Southwest US
Member Is Offline
Mood: Final exams
|
|
Concentrating hydrogen peroxide
The hydrogen peroxide I can buy off the shelf is 3-4%. There have been some instances where a more concentrated solution would be very helpful, say
30%. Is there an easy way to concentrate it? Distillation would obviously decompose the H2O2. I'm not sure if vacuum
distillation might work. I'm almost equipped to do that.
A while back, I read something suggesting bubbling air through a cold H2O2 solution would reach concentrations up to 30%. I
think the reasoning was this: keeping the solution cool prevents the decomposition, and the air flow increases the rate of H2O
evaporation. That seems too easy. It would depend on the H2O2 either not evaporating, or evaporating at a substantially slower
rate than the H2O..
I'm still getting my head wrapped around solubility and properties of solutions, so pardon my noob reasoning here.. Both H2O2
and H2O are liquid at STP and miscible, so we have a homogeneous solution. That solution has a boiling point that is likely somewhere
between the BP of the two (100 - 150C). When it evaporates, both liquids will evaporate, but the liquid with the lower BP will evaporate faster. Is
that universally true? If so, it seems like the air bubbling method _would_ concentrate the H2O2, but may be fairly
inefficient.
|
|
|
cyanureeves
National Hazard
Posts: 737
Registered: 29-8-2010
Location: Mars
Member Is Offline
Mood: No Mood
|
|
plante 1999 showed me a way to concentrate peroxide using an aquarium pump aerator.the peroxide was warmed just below boiling point on a candle wax
warmer or coffee pot(180 deg.) the air was bubbled until 1/3 of peroxide is left. i know it works because i left it unattended for a couple of hrs.
and when i got back,the stone at the end of the air tube was totally dissolved.the peroxide had also evaporated so i abandoned this before i get burnt
or something.
|
|
|
Hawkguy
Hazard to Others
Posts: 326
Registered: 10-10-2014
Location: British Columbia (Canada eh!)
Member Is Offline
Mood: Body is Ready
|
|
There are two main methods to concentrating Hydrogen Peroxide, like the pharmacy stuff.
-The first way is to heat to maybe 50 - 80 degrees Celsius, and water will evaporate off. The point is to steam off the water, so not boiling or
even slight simmering should take place. This way is also dangerous, as oxygen is released in small quantities, larger if the heating goes wrong.
-The second method involves leaving the Hydrogen Peroxide solution in a beaker or crystallizing dish, in a warm room. It should be covered, or
in a desiccating bag. The idea is for the water to slowly evaporate, and leave behind a more concentrated product. It should be left for a week or
several, depending on goal.
Good luck!
|
|
|
kt5000
Hazard to Others
Posts: 133
Registered: 27-3-2013
Location: Southwest US
Member Is Offline
Mood: Final exams
|
|
Quote: Originally posted by cyanureeves  | | when i got back,the stone at the end of the air tube was totally dissolved.the peroxide had also evaporated so i abandoned this before i get burnt or
something. |
The method I read of used an aquarium stone also. So maybe bubble through a glass pipette instead of the aquarium stone?
|
|
|
kt5000
Hazard to Others
Posts: 133
Registered: 27-3-2013
Location: Southwest US
Member Is Offline
Mood: Final exams
|
|
The oxygen being dangerous, is that only if I'm using an open flame, or does it form some other compound? I heat everything with an electric
hotplate.
|
|
|
cyanureeves
National Hazard
Posts: 737
Registered: 29-8-2010
Location: Mars
Member Is Offline
Mood: No Mood
|
|
no kt5000 the idea was not to get it to 30% concentration but since i let it go further it's concentration went way higher.i was looking for 15-30%
but it went higher so i got careless and so obviously i'm not ready for this crap! i was going to make ammonium iron sulfate.
|
|
|
Hawkguy
Hazard to Others
Posts: 326
Registered: 10-10-2014
Location: British Columbia (Canada eh!)
Member Is Offline
Mood: Body is Ready
|
|
| Quote: Originally posted by kt5000 |
The oxygen being dangerous, is that only if I'm using an open flame, or does it form some other compound? I heat everything with an electric
hotplate. |
No other compounds are formed, just that the oxygen makes the ignition of a nearby flammable material much more likely, as I have found out from
experience. You'll be fine if you use clean apparatus, a neat workspace, and if you SLOWLY heat the Hydrogen Peroxide. Remember, it should be steaming
like a hot tub in the winter, no excessive heat should be used.
|
|
|
blogfast25
International Hazard
Posts: 10562
Registered: 3-2-2008
Location: Neverland
Member Is Offline
Mood: No Mood
|
|
You can also concentrate peroxide solutions by freezing them. There's a thread on it here somewhere.
|
|
|
hyfalcon
International Hazard
Posts: 1003
Registered: 29-3-2012
Member Is Offline
Mood: No Mood
|
|
This topic has been covered extensively on the site. Does no one search anymore before starting a new thread?
|
|
|
CuReUS
National Hazard
Posts: 928
Registered: 9-9-2014
Member Is Offline
Mood: No Mood
|
|
| Quote: Originally posted by hyfalcon | | This topic has been covered extensively on the site. Does no one search anymore before starting a new thread? |
correct, this is the link to that thread
http://www.sciencemadness.org/talk/viewthread.php?tid=30193#...
|
|
|
hyfalcon
International Hazard
Posts: 1003
Registered: 29-3-2012
Member Is Offline
Mood: No Mood
|
|
I had this in mind myself.
| Code: | https://www.google.com/search?q=site%3A+sciencemadness.org+hydrogen+peroxide&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&channel=sb#rls=org.mozilla:en-US:official&channel=sb&q=site:sciencemadness.org+concentrating++hydrogen+peroxide |
Got it that time.
[Edited on 11-10-2014 by hyfalcon]
[Edited on 11-10-2014 by hyfalcon]
|
|
|
franklyn
International Hazard
Posts: 3026
Registered: 30-5-2006
Location: Da Big Apple
Member Is Offline
Mood: No Mood
|
|
http://www.sciencemadness.org/talk/viewthread.php?tid=1325
http://www.sciencemadness.org/talk/viewthread.php?tid=1325#p...
P.S.
stay away from partitionong with ether unless you're willing to end up as red mist.
.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
