rstar
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making Manganese salts from KMnO4
So....
Any Mn salt that can be made from KMnO4 ?
also tell the method to isolate the salt from other products 
"A tidy laboratory means a lazy chemist "
- Jöns Jacob Berzelius
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Hexavalent
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MnO2 can be generated by reduction, and the reaction of this with mineral acids yields some nice salts.
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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weiming1998
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Quote: Originally posted by rstar  | So....
Any Mn salt that can be made from KMnO4 ?
also tell the method to isolate the salt from other products
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Most simple manganese (II) salts can be made without much difficulty from KMnO4, via reduction, either with a MnO2 intermediate (reduction with
S2O3(-2), H2O2 or organic compounds, then dissolution of MnO2 in hot, concentrated H2SO4 or HCl) or directly to Mn2+ (with oxalic acid, hydrochloric
acid, etc.) The product can then be purified by precipitation of the Mn2+ ions as MnCO3. Reacting oxalic acid and MnO2 gives MnCO3 directly. The MnCO3
can then be dissolved in an acid to form the manganese salt of the acid.
Mn(III) salts are far more difficult to prepare. Mn (III) acetate is prepared by reacting KMnO4 with Mn (II) acetate in anhydrous acetic acid. Other
Mn (III) salts can probably be prepared analogously, but I'm not certain.
[Edited on 7-10-2012 by weiming1998]
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rstar
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How to make MnSO4 directly from KMnO4 ?
"A tidy laboratory means a lazy chemist "
- Jöns Jacob Berzelius
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weiming1998
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There are 3 possible methods that I can think of:
1, React acidified KMnO4 with an alcohol (or any reducing agents that reduces the MnO4- ion but not MnO2) to form MnO2, then dissolve MnO2 in hot,
concentrated H2SO4.
2, React KMnO4 with a mix of H2SO4 and oxalic acid. MnSO4 is formed, along with K2SO4. The K2SO4 can be crystallized out by chilling solution (the
solubility of MnSO4 decreases with increasing temperature)
3, Dissolve KMnO4 in hydrochloric acid, then precipitate out the Mn2+ as MnCO3 by the addition of Na2CO3. Dissolve MnCO3 in H2SO4.
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blogfast25
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All very creative ways to obtain something cheap from something more precious! Here's another one: oxidation of oxalic acid with KMnO4 in presence of
H2SO4. Straight MnSO4 solution results from it.
Instead, buy (or make) MnO2 or MnCO3. Cheaper and easier.
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rstar
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If i get MnCO3, i shall decompose it to MnO.
i heard MnO is green colored
can anyone post some pictures of MnO ?
"A tidy laboratory means a lazy chemist "
- Jöns Jacob Berzelius
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DJF90
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You wont isolate MnO very easily. Its a very air sensitive material, such that it is used to scrub oxygen from inert gases for gloveboxes. Maybe
heating MnCO3 to decomposition in a heavy wall ampoule under vacuum and sealing the vial when the reaction is complete is the easiest attempt to
procure a stable sample.
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CrEaTiVePyroScience
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I got a youtube video where I show you how to isolate the manganese salts from potassium permanganate.
It's a detailed instructional video , please give me feedback!
https://www.youtube.com/watch?v=Pso9FsXxiTk
Preperation and Isolation of manganese carbonate and nitrate from potassium permangante are shown.
Starting from the carbonate you can also make the sulfates , etc..
Hope this helps.
[Edited on 9-10-2012 by CrEaTiVePyroScience]
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blogfast25
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CreativePyro:
My general comment would be that considering how cheap Mn(II) salts really are, sacrificing a very useful and not-so-cheap compound like KMnO4 is a
bit ‘overkill’. These salts can be made in a variety of ways (always using a relatively weak reducing agent) from either pottery grade MnO2 (or
MnCO3) or MnO2 bearing zinc battery gunge.
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CrEaTiVePyroScience
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@Blogfast25 That's 100% true but the subject of this thread was "Making Manganese salts from KMnO4".
Anyways, I don't use it as a method to actual produce it on large scale just more to "explore" the science. And for example in the place where I live
I can get 100gram/euro KMnO4. And since I got some bad experience in attempts trying to isolate the lithium for lithium batteries I am not isolating
anymore substances from batteries although this is a good source for Mno2 , if I'm not mistaken. But there are indeed TONS of other cheaper ways to
make / obtain Mn salts.
~CPS
[Edited on 10-10-2012 by CrEaTiVePyroScience]
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