JoeChemist
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K2MnO4 conversion to KMnO4
Hey how are you all doing, I´m trying to convert K2MnO4 into KMnO4.... i´ve been able to achieve this through liquid oxidation, but out of 1 Kilo my
result is about 270 Kg (27%), any ideas on how i can raise the result %?
Edit by chemoleo: title error
[Edited on 15-8-2009 by chemoleo]
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Joauml
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well, Im not sure if I understood what you are trying to do( I don't speak english very well), but, what exactly was the metod that you have used to
oxidate the K2MnO4?
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Picric-A
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Please give us more information on what you have done... what have you used to oxidise it ect...
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kclo4
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Perhaps you can add an acid of some sort?
K2MnO4 + HX = KMNO4 + KX
I also found this:
KMnO4 + KI → K2MnO4 + ½ I2
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Jor
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Just acidify a conc. solution of K2MnO4 with sulfuric acid, and filter the formed MnO2. Because KMnO4 not very soluble, there´s probably also some
KMnO4 crystals mixed in the MnO2.
I´m not sure if boiling down the KMnO4/solution (in H2SO4) will decompose some permanganate, but I would say boil down, cool, and filter.
I have no experience with the above --> I buy my KMnO4.
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DJF90
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I'm not sure if this guy is trying to oxidise manganate (VI) or reduce manganate (VII). I'm going to guess the latter, as KMnO4 is much easier to
obtain than K2MnO4, and due to this line:
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I´m trying to convert K2MnO4 into KMnO4....
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I'm sure I saw this preparation in inorganic syntheses somewhere...
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Jor
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Well, when one wants to make KMnO4, the synthesis goes via K2MnO4.
This is because MnO2 is oxidised to K2MnO4 by heating in a crucible with KOH and KClO3 (or possibly KNO3).
So although K2MnO4 may be harder to buy, it is something wich needs to be made before KMnO4 can be synthesised.
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DJF90
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Yes I remember now. Until he says what method he's trying its hard to suggest improvements :/
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entropy51
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Both electrolysis and chlorination have been used for oxidation of manganate to permanganate, as in this patent and others:
http://www.google.com/patents/about?id=I9BOAAAAEBAJ&dq=1...
but where I live KMnO4 can be purchased cheaply in bulk at Sears, Home Depot, etc. etc. Says "Potassium Permanganate" right on the label. No muss,
no fuss.
[Edited on 15-8-2009 by entropy51]
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TIETSE
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hey use chlorine gas , you got a supersaturated solution of K2MnO4 and you put the gas in there , in few minutes all the green turns in violet
To form chlorine do the next reaction:
2 NaCl + 2 H2SO4 + MnO2 → Na2SO4 + MnSO4 + 2 H2O + Cl2
"Minds are like parachutes, they only function when they are open. "
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kclo4
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Please explain the reaction where potassium manganate is turned into potassium permanganate with Cl2 please. What does it form, KCl or hypochlorites?
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Taoiseach
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In his exact words he has multiplicated 1 kilogram of K2MnO4 into 270 kilograms. Altough this sounds like an achievement of almost biblical scale my
guess is that this is not what he really did.
If its about oxidation of K2MnO4 you have numerous options. CO2 would be the easiest:
3 K2MnO4 + 2 CO2 + H2O -------> 2 KMnO4 + MnO2 x H2O + 2 K2CO3
This is a simple disproportionation thus yields will never exceed about 60%. The remaining K2MnO4 precipates as hydrated MnO2.
Electrolytical oxidation or chlorine would allow for higher yields.
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blogfast25
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JoeChemist: anything you might possibly want to know about manganate and permanganate is here, obviously:
http://www.sciencemadness.org/talk/viewthread.php?tid=8480
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