Talk:Potassium permanganate/Archive 1

Archive 1

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)

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)

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 tourniquet...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 tourniquet) 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)

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?

If I'm not mistaken, in acidic solution the following reaction occurs:

MnO₄⁺ + Fe²⁺ + 8H⁺ → Mn²⁺ + Fe³⁺ + 4H₂O

Tomásdearg92 (talk) 00:05, 30 April 2012 (UTC)

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)

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)

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?

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)]]

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

I think that the manganese(VII) oxide will only form in significant amounts with more concentrated acid. I think the synthesis might be dependent on the dehydrating properties of concentrated sulfuric acid. As for exact concentration, I'm not really sure. I successfully prepared the oxide using drain cleaner (probably ~93% sulfuric acid), but 1 molar is pretty dilute and should be safe. Besides, the permanganate will be consumed nearly immediately during the titration, and any manganese heptoxide that forms would be reduced as well.

Storing the permanganate solution is not really a problem. After all, you should only add a small portion of this to the acidic oxalate solution so that you can find the concentration. On long standing, it does seem to decompose a bit and deposit brown MnO₂ on glassware, so you should renormalize before use. I think ferrous sulfate will react with permanganate, which will screw up your concentration and purity...

The acid is required for the titration because the manganese in permanganate is going to be reduced to Mn²⁺, and those oxide ligands need to go somewhere - they get turned into water. The half-cell reaction would be:

MnO₄^- + 5e^- + 8H⁺ → Mn²⁺ + 4H₂O

--Pyrochem (talk) 05:03, 18 May 2009 (UTC)

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)

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)

Potassium permanganate and soil carbon

How much organic C can be oxidized by 1 mol of KMnO4???

I am interested in carbon cycling. One important factor in soil carbon is the fraction that is labile (active), which comprises the organic molecules that heterotrophic microorganisms can easily metabolize (thus generating CO2). One method for labile C assessment is to react soil with 0.02M KMnO4, and measure the change in KMnO4 concentration. A couple research papers from the '90s use this method, and assume that 1 mol KMnO4 is consumed (Mn7 --> Mn2) in the oxidation of 0.75 mol (9 g) of C. There is no citation provided for this conversion factor. Does this make sense to anyone out there. Does it come from simple stoichiometry or an understanding of potential energies of oxidation? Wetbook71 (talk) 22:45, 8 August 2008 (UTC)

inconsistency

" Acidic solutions of permanganate are reduced to the faintly pink manganese(II) sulfate ([Mn(H₂O)₆]²⁺). "

am I right that manganese(II) sulfate is not the same as [Mn(H₂O)₆]²⁺ ? this seems wrong to me, especially as I don't really see where the S came from. —Preceding unsigned comment added by 62.238.182.126 (talk) 10:07, 19 May 2009 (UTC)

went ahead and changed it, as my BINAS seems to give an entirely different reaction(MnO₄^- + 8H⁺ + 5e^- --> Mn²⁺ + 4 H₂O

Cocaine

I've heard potassium permanganate being used in the production and processing of cocaine (http://cocaine.org/process.html). Anyone know if this is true and know of some reliable sources? Gregcaletta (talk) 12:05, 17 September 2009 (UTC)

I use sodium permanganate(NaMnO4) for groundwater remediation of chlorinated solvents and am required to fill out paperwork to send to the DEA as a result of it's potential use in the refining of cocaine. Potassium permanganate could also be used since it is just a different salt attached to the permanganate.

Crowboy70 (talk) 20:58, 20 May 2010 (UTC)Crowboy

Mass of crystals?

Hello. I have a odd mass of crytsal wich looks very simaler to this compound in color. it looks rather like a pecie of sandstone made of this compound. I have been trying to identfy t for quite a while, most often, I have been told it is etiher bornite, chalcopyrte, covalite etc, but it only reseblems them in color, not in any other way. I was wondering if it chould be a fused mass of Potassium pergmanganate crystals? It is around an inch long, and manybe 5 centmeters thick. Here's an image of a simeler speciman I found on google images: http://images.blog-24.com/600000/597000/597061.jpg

Thank you. Jabberwock xeno (talk) 19:29, 9 January 2010 (UTC)

Not called potassium permanganate anymore

should the article title not use the substances proper name-Potassium manganate(VII)? I know the name is listed in the article, but surely it should be the title too, perhaps with a mention of permanganate being its old name?

Doktordoris (talk) 23:44, 17 July 2010 (UTC)

Potassium manganate (VII) is the systematic name, but potassium permanganate is the most common term in use. Madgenberyl (talk) 19:15, 31 May 2011 (UTC)

Convection currents

When I went to school, potassium permanganate was used in the science lab to demonstrate convection currents. Basically, we would put a little into a flask of water over a heat source and watch it swirl around. Is this a widespread use?

Of course, with this being a demonstration purpose, you could debate whether it counts as a practical use. But I think it would be good to find information on what properties of the substance make it the material of choice for this experiment. -- Smjg (talk) 16:21, 12 August 2010 (UTC)

The property that makes it useful is its colour. It's purple, so you can see it swirling around. Madgenberyl (talk) 19:13, 31 May 2011 (UTC)

What is the function of Potassium Permanganate in Boiler Water Treatment.

One of the Boiler manufacturer lists KMnO4 consumption in Boiler water and recommends value that should be 500 ppm.

What is the purpose of KMnO4 in Boiler Water treatment, with which problem this relates?

Apparently it is used to destroy compounds that corrode the plumbing. Seems strange to me too, but that's what the book (Ullmann's says).--Smokefoot (talk) 13:35, 16 November 2012 (UTC)

Analytical Use: unparseable sentence

Pre-treated with potassium permanganate, to obliterate Congo red reactivity, was thought to be definitive for AA amyloidosis;[28] this is now generally considered to be unreliable.[29][30]

What "was thought to be definitive" ? I would fix the grammar myself, but I have no idea what is trying to be said... 71.63.4.110 (talk) 18:16, 12 October 2014 (UTC)

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.

Above comment was first posted in March 2006, and the potassium manganate article created by Smokefoot in May 2006. Wasn't archived by Lowercase sigmabot III in 2017, probably due to no date in the section. Now that I've added a signed comment, hope bot will archive in due course. Pelagic (talk) 20:08, 22 March 2017 (UTC)

Onoway pink water

Incident was also mentioned in Australian media [2]. Didn't add that to article ref's to avoid undue emphasis, but posting link here in case it is of interest (or in case CBS link goes dead like the Northern Advocate one (Wayback Machine says "no", because ... robots.txt). Pelagic (talk) 20:19, 22 March 2017 (UTC)

I can't resist speculating, what did residents say when their water turned pink? "O, no way!" Pelagic (talk) 20:19, 22 March 2017 (UTC)

Baeyer's reagent

why is Baeyer's reagent a standalone article? Jytdog (talk) 19:40, 9 October 2017 (UTC)

Great catch of a stray. Unless we hear suggestions otherwise, I will migrate that content and convert Baeyer's reagent into #REDIRECT Potassium permanganate#Baeyer's reagent.--Smokefoot (talk) 21:10, 9 October 2017 (UTC)

:) Jytdog (talk) 05:23, 13 October 2017 (UTC)

Life science

What happens when you mix water with potassium permanganate 154.73.120.122 (talk) 22:44, 9 November 2022 (UTC)

it dissolves. --Smokefoot (talk) 14:49, 10 November 2022 (UTC)