Sciencemadness Discussion Board

hydrogen peroxide from sodium peroxide

symboom - 31-3-2011 at 13:03

so i burned sodium in pure oxygen was wondering it i mix sodium peroxide with sulfuric acid. (sense bases decompose peroxide) to form sodium sulfate which should help absorb the water from the solution and h2o2 how can i separate it with out boiling it out in a vacuum chamber at room temp
any sugestions

m1tanker78 - 31-3-2011 at 15:44

The only thing that comes to mind is to chill your resulting solution. This should precipitate some of the sulfate and freeze *some* of the water. I've never tried this with sulfuric acid so I don't know the particulars of it. Sounds like a recipe for piranha etch, though.

I think you'll find that unless you add stabilizer(s) to the solution, it's going to decompose spontaneously even in an acid. It's sure to decompose if you add the Na2O2 too quickly even if you start out with a chilled acid solution. This is due to the exothermic nature of the reaction and the hot spots that are generated on contact.

I suggest you try this on a small scale first and use extreme caution with a blend of H2SO4 and H2O2.


symboom - 31-3-2011 at 17:30

i was thinking of using an excess of sodium peroxide to sulfuric acid>sodium sulfate and h2o2 and probably going to be some water and darn,and some sodium hydroxide. i guess excess of sulfuric acid to prevent sodium hydroxide from forming
> thanks for the tips

or maybe adding baking soda to the perhana solution

>Sulfuric Acid<has more water in it>
Melting point 50 °F
Boiling point 639 °F

Pure disulfuric acid itself is a solid at room temperature, melting at 36 °C

>Hydrogen Peroxide_________>Water
Melting point 31 F_________ Melting point 32 F
Boiling point 302 F_________ Boiling point 212 F

[Edited on 1-4-2011 by symboom]

[Edited on 1-4-2011 by symboom]

Maya - 8-4-2011 at 12:09

to make hydrogen peroxide,

use barium peroxide instead then chill down to freezing as suggested.

you will get much better results

AndersHoveland - 12-3-2013 at 12:49

To make H2O2 from Na2O2, just add acid. Preferrably not HCl, since this causes decomposition, and furthermore any chloride ion contamination can slowly catalyze the decomposition of H2O2 in storage. Dilute sulfuric acid works well, since the Na2SO4 byproduct becomes much less soluble at ice cold temperatures, and can mostly be precipitated out.

Na2O2 + H2SO4(aq) --> Na2SO4(aq) + H2O2

One other thing to add, be sure to use a slight excess of acid, because while Na2O2 is stable, alkaline solutions of hydrogen peroxide gradually decompose. In other words, wet Na2O2 will gradually give off bubbles of O2.

It is also possible to do the reverse, to make calcium peroxide from hydrogen peroxide.

Calcium Peroxide

To prepare the calcium peroxide octohydrate, CaO2*(8)H2O,

11g of calcium chloride hexahydrate, CaCl2•(6)H2O, are dissolved in 5ml of water. Then 50ml 3% hydrogen peroxide are added. Finally 7ml of concentrated ammonia solution which has been previously dissolved in 100ml of water is added. If this procedure done at a temperature of 55°C, or if only 30ml of water are used for the ammonia at 20°C, a lower hydrate is obtained which contains only 0.4 molecules of H2O for each CaO2. The yield is about 4.5g of the octohydrate, or 8.0g of the 0.4-hydrate.

It might be a better idea to use calcium nitrate, or possibly calcium acetate, because chloride ions very slowly catalyze the decomposition of hydrogen peroxide, and traces of chloride ion likely will contaminate the CaO2 product, which might cause it to degrade in storage.

The equation is:

CaCl2 + H2O2 + (2)NH4OH --> CaO2 + (2)NH4Cl + (2)H2O

The presence of excess ammonia is important to precipitate out the calcium peroxide, as ammonium chloride is slightly acidic and calcium peroxide is alkaline. Unless using calcium nitrate, it is probably not a good idea to let the reaction stand too long before filtering out the calcium peroxide.

Pure calcium peroxide is best prepared by careful dehydration of the octahydrate. Ideally the surrounding gas should be free from any carbon dioxide (which can be achieved by bubbling air through a solution of sodium hydroxide). The hydrate is warmed under reduced pressure. Alternatively, the near anhydrous CaO2 precipitates directly out of solution at a temperature of 70 °C as a beige colored solid.

Calcium Superoxide
The decomposition of solid calcium peroxide diperoxyhydrate, CaO2•(2)H2O2, was found to yield calcium superoxide, Ca(O2)2, with four oxygen atoms for each calcium atom! The decomposition was carried out at 40 °C for one hour under vacuum (only 0.006 mmHg pressure). Although typical yields are around 40%, samples have been prepared showing superoxide contents higher than the theoretical 58.4% expected from a disproportionation reaction. Superoxide reacts with water to give off oxygen.

[Edited on 12-3-2013 by AndersHoveland]

Adas - 13-3-2013 at 07:16

Thanks, Anders! I have just made some CaO2, it looks like a good oxidizer! :) I didn't wash it too much since it is a PITA to filter it, it takes too long. I used concentrated reactants (anhyd. CaCl2, conc. NH3 soln. and 30% H2O2). I got the percipitate immediately.

Very easy synth, common reactants and good usefulness. Nice experiment for an amateur.

EDIT: I am adding a video for ya.

[Edited on 13-3-2013 by Adas]

madscientist - 28-3-2013 at 05:25

And where are those procedures from, Anders?

symboom - 16-6-2017 at 13:27

Excerp from

To prepare the calcium peroxide 11g of calcium chloride are dissolved in 5 ml of water and treated with 50ml of fresh 3% hydrogen peroxide and then with 7 ml of concentrated ammonia solution in 100 ml of water. If this procedure is carried out at 55° C, or if only 30ml of water are used for the ammonia at 20° C.

So this actually works I got a percipitate of I guess calcium peroxide and after a little while foaming attempted at room temperature
Going to attempt at chilled temperature im guessing it behaves like copper peroxide not as vigerous though a little foaming

I am using 3%

someone made calcium peroxide first :-)
Congrats adas

[Edited on 16-6-2017 by symboom]