Sciencemadness Discussion Board

Old peroxide

papaya - 30-9-2013 at 06:02

Hi, recently I found a glass bottle with 0.5L of 10+ years old hydrogen peroxide - it mostly decomposed, because the reaction with KMnO4 is very slow (hard to see odd bubbles coming off). It still colors starch- iodide paper faint blue, I estimate it's concentration <1% (won't worry to waste time on titration). Question - what to do with it, where can it be utilized having such a low concentration ?

bfesser - 30-9-2013 at 07:26

It can be utilized in cleaning the sink drain.

papaya - 30-9-2013 at 08:37

I hoped to convert it into something useful (even the yield of the X is 10g ) - what about peroxychromates, does it work with concentrated peroxide only?

woelen - 30-9-2013 at 08:49

If it is so weak that a reaction with KMnO4 hardly shows any bubbles, then it is much less than 1%. Even a 1% solution still gives a good fizzle with KMnO4.

Just dump it and use the glass bottle for storing something more useful.

Fantasma4500 - 30-9-2013 at 08:55

you could concentrate it perhaps
simply keep heat at 100*C max, or well just keep it at a fast evaporation rate with only small bubbles, 70*C should work..
plante1999 wrote about it, IIRC approx 95% yield, as in 5% H2O2 lost, concentrating was as much as 80% (again, not 100% sure on this)

bfesser - 30-9-2013 at 11:09

Drain cleaner isn't useful? With such a low (<em>estimated</em>;) concentration, I doubt you'll come up with anything that's worth the effort. If you're unwilling to "waste time" titrating it, why waste time trying to use it?
Quote: Originally posted by woelen  
Just dump it and use the glass bottle for storing something more useful.
Do this and stop wasting all of our time. :P

[Edited on 30.9.13 by bfesser]

bismuthate - 30-9-2013 at 12:26

just mix it with vinegar or HCL and let it sit in some slightly dirty glassware for a while.
(it won't work very fast due to the low concentration)

Mailinmypocket - 2-10-2013 at 11:49

Mix it with epsom salts and give yourself a foot bath to relax from racking your brain by thinking of how to use it ;)