Sciencemadness Discussion Board

H2O2 shelf life?

GreenD - 5-3-2012 at 12:06

Does anyone know how long this stuff can last in a <0°C Freezer?

Bot0nist - 5-3-2012 at 12:17

Is it stabilized?

GreenD - 5-3-2012 at 12:40

Quote: Originally posted by Bot0nist  
Is it stabilized?


I think it has some stabilizer. I reacted it with some dyes that should oxidize on contact with H2O2 and no visual change observed.

The date on the bottle is multiple years old.

Bot0nist - 5-3-2012 at 12:45

You could do a titration by measuring the volume of decomposed gasses. Catalyze the release with MnO<sub>2</sub> and capture the oxygen in an inverted graduated cylinder filled with water. The gas will displace the water, and give you a volume to work with. This will allow you to determine the amount of decomposition the peroxide has experienced, and give you a very close estimate of its concentration.

Hexavalent - 5-3-2012 at 12:45

The way I measure H2O2 concentration is by reacting it with an oxidant when new, and measuring the volume of O2 produced. Then, every few months or so, I perform the same reaction and note how much less gas is collected.

GreenD - is your peroxide in an amber glass bottle, and, if, so, where in your lab is it kept?


(DAMN, Bot0nist just beat me to the post of its reactions and gas production)

[Edited on 5-3-2012 by Hexavalent]

GreenD - 5-3-2012 at 12:57

If I find some MnO2 I'll do that...

I believe it is in a PPE bottle, in a lab freezer at around -20° C? It might be -5°C...

Hexavalent - 5-3-2012 at 13:00

You can use a lot of catalysts, not just MnO2. KMnO4 works well, as does FeSO4.

If you need MnO2, though, then open up a good lantern battery and you'll find about 500g of the stuff!:)

neptunium - 5-3-2012 at 13:02

if sealed away from light and kept cool it should last a pretty long time ...if sealed!

[Edited on 5-3-2012 by neptunium]

GreenD - 5-3-2012 at 13:02

Quote: Originally posted by Hexavalent  
You can use a lot of catalysts, not just MnO2. KMnO4 works well, as does FeSO4.

If you need MnO2, though, then open up a good lantern battery and you'll find about 500g of the stuff!:)


Ok. I will try to find an oxidizer. What is the gas that bubbles off? O2?

Hexavalent - 7-3-2012 at 11:52

Yes;

2H2O2 ----> 2H2O + O2

Two moles of hydrogen peroxide decompose to give two moles of water and one mole of molecular oxygen gas.