how do i make 30% hydrogen peroxide?

Question

i need a 30% consentration of hydrogen peroxide but i only can get it in a 6% consentration how do i go about uping the consentrationit in a simple way

Answer 1

As said above, letting it evaporate might work....
determining the percentage of the resulting mixture is easy, just measure the volume(do the evaporation in a largish beaker so you don't have to put it in a new container everytime), weigh it(leave the beaker on a scale),and look for grams divided by mililiters to equal about 1.19(the specific gravity of a 30% hydrogen peroxide solution).

Personally, I'd rather use vacuum distillation than just letting it evaporate. It's much quicker, but slightly more equipment intensive and slightly more dangerous.

I know that in the States you can get up to at least 50% hydrogen peroxide online (try froogle). You might be better off getting this and adding distilled water to it.

Answer 2

For most solutions, you could just boil some of the water off. Unfortunately, hydrogen peroxide would most likely decompose at those temperatures, and you'd end up with plain water if you tried that. You might be able to let it sit out. The water should evaporate a bit faster than the H2O2, as the boiling point of H2O2 is 114 Celcius vs. water's 100 Celcius. How you'd know when you got to 30% is difficult, though, since both substances will evaporate. And don't let it evaporate to dryness, since peroxides tend to be explosive dry. Good luck.

Answer 3

On peroxide bottles is a warning not to keep them in a warm place (over 30deg. C) and to keep the bottle tightly closed. This implies that H2O2 at elevated temperatures breaks down into oxygen and H2O (plain water). Possibly you can buy peroxide in different strengths (up to 30% for hair coloring). If not, check out the German rocket development during the second world war on internet. Their rockets ran on peroxide.