concentrate 3% hydrogen peroxide methodes?

[MCtiaguinho]

Hi, i need a 40-50% h2o2 solution.

 

I have 3% h2o2 and i saw 2 methodes for concentrate, boiling and freezing.

 

So my questions are:

 

Freezing:

 

witch temp (ºc) my freezer needs to be to freeze water and left the h2o2?

 

and how much hours i need to get all the water freezed

 

Boiling:

 

witch temp i need to have to evaporate water and dont decompose h2o2?

 

 

Thank you

 

ps: sry for my english

[al93535]

Buy a liter of 40 volume h2o2 (12%) at any beauty supply. Or get 27% from numerous pool and spa supply stores. Or just order what you need from a chemical supply store. Your never going to get that concentration from 3%.

[Arthur]

3% is available in these troubled times because it's very hard to concentrate to anything pyro usable. Sadly it's usually a component of terror weapons so you have probably brought attention to your hobby.

[schroedinger]

What for do you wan`t to Hydrogenperoxide.

 

The only way you can concentrate that, is to boil it, until it has a concentration of > 20% better > 40%.

Then freeze out the Hydrogenperoxide.

Whit -21 °K you will get > 60%.

But be aware that stuff allready get`s nasty.
Also be aware that the Boiling step has a loss of 40 - 60%.

And don`t use a distill, if you go to high in that it can go explosiv and send Glas everywhere.

[MCtiaguinho]

hi,

Thanks everybody for the fast answer.

 

I know i can build very powerful explosives but inst what i want (i dont mess with very sensitive explosives only black powder or similar )

 

and i know that h2o2 is very nasty a very strong oxidizer

 

negative kelvin? o.O do you mean ºc?

 

al93535 i search a lot for that % but i didnt find, and i dont want to buy because i want to make a home lab.

 

 

so i need to boil down my 3% to 20%

and then freezing?

Thank you all

Edited January 30, 2014 by MCtiaguinho

[schroedinger]

Well of course it's Celsius.

 

Remember whith all the loss you get, you will have a maximum yield of about 1/3 after the whole process. This mean if you buy 1L of 3% H2O2 you can harvest a max about 30ml of 30% H2O2. If you go higher you can be sure that you won't get any yield, as you will lose everything when transfering from one to another bucket.

 

So look and yust buy 10-12% stuff. That stuff is strong enough for most lab purposes and available as hair bleach.

[MCtiaguinho]

hi,

i have 2L and i ill evaporate 1,8L so i ill have a nice %

 

to dont decompose the h2o2 i need to have something like ºC 100 -ºC 110 right?

 

Thank you

[MrB]

I looked in to this slightly, more as a thought experiment then for any real reasons, i still got a good source for 35-40% stuff, and i think i know a source for 98% as well. (rocketry use, didn't really test it, but pre-buy checks on the reseller checks out. They have the legal permits to store, and sell the stuff.)

Anyway. While boiling the stuff works, your much better of using a vaccum-pump. Hydrogen peroxid isn't really that stable, has to be stored quite "cold" not to break down over time, and boiling it brings fairly large losses. inducing boiling at storage temperature, is a lot less destructive.

 

The main problem with upping the % is simply, you'll never know what grade the stuff you got, actually is.

B!

[JMAPscience]

I just steam off about 87% and get a good and conc. for making O2 or making peroxides and oxidizers.

[rogeryermaw]

if you boil, make super sure your GLASS vessel is absolutely spotlessly clean. any contamination WILL result in decomposition. at high concentrations this decomp can be very...erm...energetic. if you freeze(this is a method i have used)you will need to perform more than one freezing cycle. watch it closely. as it turns to slush, decant off the liquid. to approximate the molarity of your product you will need to do some calculations. i won't spoonfeed you but i will send you in the right direction. on a test tube scale, you can decompose H2O2 with various compounds. MnO2 is popular. decomposition with this compound will result in release of O2.

 

so...how many moles of O2 will be released from a known quantity of H2O2? calculate!! fill a graduated cylinder with water and turn it upside down in a water filled tub. H2O2 in a test tube. stopper that fits tube run hose from stopper into the upturned cylinder. add compound to test tube. allow gas to displace water from cylinder. note ml of displacement. calculate ml of oxygen gas and ml of H2O2 you start with. run calculations to achieve molarity of your H2O2. you figure out the rest.

Edited August 16, 2014 by rogeryermaw

[Cookieman]

Here is a link to where I buy mine. It's 35% concentrate.

 

http://www.upayanaturals.com/SearchResults.asp?Search=hydrogen+peroxide&Search.x=9&Search.y=3