All you chemists out there I need your expert advice! Yesterday a teacher did an experiment with potassium permanganate and sulfuric acid. No notice, no information just "do we have these chemicals, great see ya later" type thing. So I googled "potassium permanganate and sulfuric acid" and found out that mixing potassium permanganate with concentrated sufuric acid has a reaction where an alcohol soaked material held over the mixture catches fire and that 'explosive' manganese oxide is produced. I think only 5M sulfuric acid was used not concentrated.
OK so with this bit of info I figure disposal of the leftovers needs a bit of care. I tipped the leftovers into paper and wrapped that up ready to go in the bin, but then I noticed it was feeling warm and yep smoke started to come off the package. Im feeling pretty mad and will be having words to the teacher about this.
Anyway in the meantime my question is is there a way to neutralise the chemical mixture to render it safe for disposal?? Till I know what is best it is sitting in a metal bucket in the fume cupboard.
Joy
Hi Joy,
This reaction will stay hot for a time so be careful.
Leave it in the bucket in the fumehood,turn on the fumehood and add lots of water to the mixture....when it has stopped reacting and is cool wash it down the sink with copious quantities of water.
Discourage him from doing this reaction and be aware ammonium dichromate and acid have a similar result(the old volcano reaction)and the product is a carcingen.
It was his responsibility to warn you of the result.
If you are ever worried about the products of a reaction leave it in the fumehood,this is the safest place.
The best option for this mixture is to discard this into sewage waste. This may sound drastic but for this mixture this will no doubt cause a fire.... The safest way to dispose of this mixture is with copious amounts of water.
As I said this may be a bit drastic but the safest way for all end users would be this option.
To have this mixture enter the waterways is not a problem most of the Permanganate is in a environmentally stable form.
The one thing that is a concern to me is the alcohol present. hmmm...
Cheers,
Robb.....
Dr Robert Crosdale. MRACI. NSS. NSSA. NASA.
Ph.D (Chem), Post Grad Ph.D (Physics), M.Ed, B.Sc (Hons), Dip. Appl. Sc. (Chem)
Lake Munmorah High School.
University of New England.
University of New South Wales.
University of Newcastle.
To understand the Universe from our perspective, we need to look towards our own backyard first for answers.
Thanks guys. I have found out that the teacher also did a similar experiment where glycerol is added to the potassium permanganate. I googled and discovered this produces white smoke and a purple flame. How nice! Specky for the kids no doubt but it would have been nice to have been informed!!
ri is on the money, the Pot. Permanganate is used in incendries where they inject Glycerol into ping pong balls filled with the Pot. Permanganate and they simply drop them from helicopters.
(Dont want to forget which oine you filled otherwise it will be a quick landing).
I'm not going to comment on the Pot. Permanganate experiment you use for the kids because it is a great way to show exothermic, volcano, spectroscopic colour, Alkanol, combination, chemical, reduction, temperature experiments from just those two chemicals. Sooooo versatile...
Cheers,
Robb.....
Dr Robert Crosdale. MRACI. NSS. NSSA. NASA.
Ph.D (Chem), Post Grad Ph.D (Physics), M.Ed, B.Sc (Hons), Dip. Appl. Sc. (Chem)
Lake Munmorah High School.
University of New England.
University of New South Wales.
University of Newcastle.
To understand the Universe from our perspective, we need to look towards our own backyard first for answers.
Till I know what is best it is sitting in a metal bucket in the fume cupboard. 
