Talk:Potassium permanganate

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[edit] Glycerine

I remember a high school chemistry teacher saying that pot. permanganate will spontaneously combust in the presence of glycerine. True? Likely? Mixing it up with something else?

Yes, solid KMnO4 is a very strong oxidizer, which when mixed with pure glycerine, will cause a highly exothermic chemical reaction to take place. This reaction would turn red hot as a spontaneous "combustion" which would melt a glass or other container holding the reacting contents and could ignite anything flammable nearby. I have personally seen a demonstration of this reaction, except nothing flammable nearby was ignited. A reaction of this sort could take place when solid KMnO4 is mixed with all kinds of organic materials. Aqueous solutions of KMnO4 are much less dangerous, especially when diluted. Also, I have heard, but not witnessed, that mixing solid KMnO4 with concentrated sulfuric acid causes an explosion. H Padleckas 08:28, 12 Apr 2005 (UTC)

[edit] Taste

Can anyone verify the taste of KMnO4? According to this article, it taste sweet. However, according to my friend it does not taste sweet. He said it taste bitter. I did any experiment eariler today that involved KMnO4, so I went to taste it. Apparently it seems that my friend is right. The taste is weird, but I would definitely not call it sweet. Bitter is a better term to describe it.

  • Well I'm certainly not going to try myself! It apparently doesn't have a very strong taste, based on the testimony of a friend of mine who had to use it for emergency water purification while trekking. Physchim62 22:50, 24 August 2005 (UTC)
The page I linked to describes it as having a "sweet, astringent taste" raptor 15:14, 12 October 2006 (UTC)
KMnO4 solution in water has metallic taste.76.222.199.53 00:03, 14 July 2007 (UTC)

[edit] Snake bites

I heard something about potassium permanganate being used to treat snake bites, does anyone know about it? --200.118.2.214 19:27, 11 October 2005 (UTC)

The potassium permanganate was predominately used for black mamba bites in Africa (Ghana) finding that the properties could work for any snake bite. HOW TO USE IT: First constrict the area to stop blood flow in the limb with a turnoquet...then make an incision across the bite (now most medical proffesionals will advise not to do this because is well spread even more venom thats why we have applied a turnoquet) then after the incision pack the incision with Potassium Permanganate —Preceding unsigned comment added by 158.135.245.192 (talk) 21:03, 21 January 2008 (UTC)

[edit] neutralizing agent

Do you know the best possible neutralizing agent against aqueous solutions of potassium permanganate (I mean reduction point of wiev) to avoid/increase the feature of flammable?

  • Aqueous iron(II) sulfate solution works well for small quantities. The fire risk with solutions of KMnO4 is not very high, it is the solid compound which really poses a risk. Physchim62 13:32, 18 October 2005 (UTC)
What are the resulting compounds of iron(II) sulfate and KMnO4, anyway?

[edit] "rejuvenation" of potassium permanganate

Potassium permanganate is known to be used at the discoloration process of jeans . A way of application is by impregnating pumice stones in a potassium permanganate solution and after that remove the pumice and let them dry . In this way pumice stones "encapsulate" an amount of permanganate and can be used to "stonewash" jeans and diminish the shade of jeans at the same time . This application results in a fashionable effect . As a result we get an inormous amount of pumice stones having a brown shade.(This is the inactivated form of potassium permanganate, magnesium oxide). Is it possible to "rejuvenate" the pumice? Is it possible to regain some of the quantity of permanganate by "oxidation" of the magnesium oxide?

Although potassium permanganate is made from manganese dioxide, the process would require that the MnO2 was extracted from the stones. My guess is that this would not be economically viable. However, the stones could be re-impregnated with potassium permanganate to recharge them.

[edit] potassium maganate redirect

The link for potassium manganate redirects to potassium permanganate. This is incorrect. Potassium permanganate has the formula KMnO4 (Mn is in the +7 oxidation state)and is purple, while potassium manganate has the formula K2MnO4 (Mn is in the +6 oxidation state) and is dark green. These are two separate compunds, and should be listed as such.


[edit] Ozone does not arise from KMNO4?

I removed the comment that H2SO4 + KMNO4 gives ozone. I have seen no mention of this conversion in my reading. H2SO4 gives Mn2O7, which is slightly volatile and a nasty oxidant, which could explain the ignition of paper over H2SO4/KMnO4 mixtures. See Mn2O7. If anyone has a citation supporting the fascinating ozone possibility, feel free to over-ride my deletion, but do add a journal or book reference.--Smokefoot 16:12, 2 May 2006 (UTC)

Agree: Mn2O7 is volatile, so you might get a smell of ozone from this reaction, but I cant see anyone preparing large quantities of O3, the thermodynamics just arent there. Physchim62 (talk) 12:43, 3 May 2006 (UTC)

Well, apparently I am wrong and there is something to this ozone thing. Dzhabiev, T. S.; Denisov, N. N.; Moiseev, D. N. and Shilov, A. E., "Formation of ozone during the reduction of potassium permanganate in sulfuric acid solutions", Russian Journal of Physical Chemistry, 2005, 79, 1755-1760 Barthel, H. and Duvinage, B., "Clemens Winkler. His experiments with ozone in 1892", Praxis der Naturwissenschaften, Chemie, 2000, 49, 18. Abstract: "A lecture demonstration is described concerning a modified version of the historical ozone expt. of Clemens Winkler in 1892. A gutter, about 2 m long and closed at both ends, is filled with 30-50 mL EtOH. 0.5 Mg KMnO4 is given to 3 mL of concd. H2SO4 and stirred with a glass bar. When the tip of the glass bar is hold over the EtOH surface a flame appears immediately which is spread over the whole gutter. [on SciFinder (R)]" So I will go back and undo some of my deletions: sic transit arrogance or something like that.--Smokefoot 19:36, 3 May 2006 (UTC)


[edit] NFPA 704 Rating

The ranking on this page is incorrect. According to http://www.answers.com/topic/list-of-nfpa-704-ratings#wp-P and http://www.sciencelab.com/msds.php?msdsld=9927406 the ranking should be a 1 in blue, and 0 in everything else with an "OX" in the white square. Someone should change this if they find agreeing evidence.

The International chemical safety card cited in the article doesn't give any hints, and the ratings quoted above seem reasonable. comments anyone? Physchim62 (talk) 16:07, 13 October 2006 (UTC)

The major manufacturers of this chemical (Aldrich, Fisher, Acros, etc.) suggest a 3-0-3 rating or something close. This compound is a very strong oxidizing agent and should at least be listed as a 3 in reactivity. It is also reasonably toxic considering the type of reaction it has with ones skin, eyes, mouth excreta. The bottom line is that it is irresponsible to have such a low hazard rating on a chemical that is no where near the safety specifications suggested by a 1-0-0 rating. cckst11, 10/03/2007

Aldrich gives it a 1-0-3 rating and I will change it to that. Well established and commonly recognised safety ratings should be used. I have witnessed the effects that overly cautious (but nevertheless incorrect) NFPA ratings have on people working with those compounds. They desensitize people and make them vulnerable once they have to handle really nasty reagemnts.Xenofonos (talk) 23:18, 3 April 2008 (UTC)

[edit] Teargas

On the 1991 film about South African right- wingers The Leader, his driver and the driver's wife by Nick Broomfield a man named J.P. Meyer says if Condy's Crystals and formalin are mixed teargas is created. —The preceding unsigned comment was added by 82.28.1.84 (talk) 13:55, 13 January 2007 (UTC).

No, you make formic acid, which is unpleasant but not what is usually refrred to as tear gas. Physchim62 (talk) 15:03, 13 January 2007 (UTC)

But it was a gas which rose and caused all persons present to leave the room in which it was set off and the man who makes it J.P. Meyer says it's used to 'break up NP (South Afrian National Party) meetings' and so it was obviously treated as teargas and is a painful irritant.

I never said that I would like to try the experiment, especially not in an enclosed space! Formic acid is the active component in most ant stings. Physchim62 (talk) 17:13, 18 January 2007 (UTC)

Fair enough but it's teargas because it makes people cry and run around. Agreed?

[edit] Missspelling?

down in hazards theres a sentance "such as a pouder mixture of KMnO4" is it supposed to be powder? im not good with science so i didnt want to change it and find out pouder meant something.

[edit] Delete Section

I think that the essay like Hydrogen Peroxide section should be deleted - in its current form there is no way (in my opinion) for it to be 'wikified'. If the section is important enough to warrant inclusion someone would pretty much have to rewrite it from scratch anyway - at the moment it's a bit embarrassing (once again in my opinion). Any thoughts? —The preceding unsigned comment was added by 138.251.248.140 (talk) 16:29, 13 April 2007 (UTC). Sorry forgot to sign (and login) [[Guest9999 16:31, 13 April 2007 (UTC)]]

Since there were no objections I deleted the section. [[Guest9999 11:01, 14 April 2007 (UTC)]]

[edit] How to not accidentally make Manganese(VII) oxide

Does anyone know the specifics on this?

I have read several analytical chemistry books which discuss normalizing potassium permanganate

They dissolve sodium oxalate in something near one molar sulfuric acid. It is heated so the temp remains about 60 degrees Celsius and appoximately 0.1 molar potassium permanganate is titrated into it.

However, that is combining KMnO4 with dilute sulfuric acid. With my interpretatio the wikipedia article states that could make the explosive compound. However, I doubt so many books I have read tell accidental explosive procedures. What concentration of sulfuric acid is safe and for how long? What is the best way to store it? I guess throw in Fe(II)Sulfate solution and also make sure pH is near neutral but I wandered if anyone knows for sure. Why is acid nesecary in the first place? I realize only high concnetrations or the solid form of KMnO4 is likely to combust a solvent in flames. However, I am worried about making Manganese(VII) oxide.

Thanks for any help, I realize this is a lot of questions. 67.79.200.162No Explosions Please

[edit] Contradictory information

The "Acids and KMnO4" section is contradicted by the "Hazards" section. One says that Mn2O7 is produced by concentrated acid and the other, dilute acid. Anybody know which is correct? NBeddoe 12:00, 10 July 2007 (UTC)

I believe it's concentrated (>10%) that people should worry most about. Dilute H2SO4 will create the compound on a much smaller scale, I believe the water cools, further dilutes and stabilizes any resulting Mn2O7 to the degree that it isn't very likely to explode (in small quantities, anyway). I've seen someone recommend using KMnO4 in dilute H2SO4 to test for the presence of H2SO3. Link is here: [1] I've actually tried this before with 5% H2SO4, and nothing spectacular happened, other than the KMnO4 reducing to MnO2. 97.82.247.200 22:12, 5 August 2007 (UTC)

[edit] Links

Potassium permanganate#Permanganate value is a link for Water Supply (Water Quality) Regulations 1989. I am no great shakes as a chemist so if my contribution to this article is edited please re-establish the link. CyrilThePig4 12:58, 6 September 2007 (UTC)