lalalympo
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Manganese nitrate synthesis
I was wondering if it's possible to make manganese nitrate by the reaction of nitric acid and manganese carbonate according to the reaction: MnCO3 + 2
HNO3 -> Mn(NO3)2 + H2O + CO2. It seems very simple, way easier than the method using oxalic acid. MnCO3 is insoluble in water, but maybe it still
reacts with acid the same way CaCO3 does?
I found a pottery store that sells manganese carbonate, it's probably loaded with impurities, especially considering its low pricetag, but I could do
some re-crystallization with the manganese nitrate.
[Edited on 5-12-2017 by lalalympo]
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happyfooddance
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Of course.
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gdflp
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Thread Moved
5-12-2017 at 14:03 |
Texium
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I wouldn't be so sure. Nitric acid might oxidize Mn(II) to Mn(IV), giving you manganese dioxide and NOx. Try it out on a small scale and see if you
get a nice light pink solution or a bunch of brown crud and nasty fumes.
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DraconicAcid
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I doubt nitric acid will oxidize Mn(II) to MnO2- even in a concentrated solution of nitric acid, it requires a stronger oxidizing agent than nitrate
(chlorate works). It's easier to oxidize to MnO2 in more basic solution, but the the nitrate ion doesn't act as an oxidant.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Texium
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Alright, I did a quick experiment out of curiosity. In a test tube, I made a suspension of manganese carbonate in water and added a few drops of
azeotropic nitric acid. It fizzed and dissolved quickly to yield a pale pink solution. Gas given off was odorless. Looks like DraconicAcid is correct,
and manganese(II) nitrate should be stable.
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Boffis
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Its easy to make manganese nitrate solution but its quite another to obtain manganese nitrate crystals. I found it extremely soluble and the final
crystals extremely deliquescent. MnCO3 dissolves in hot 30% nitric acid fairly readily, excess carbonate ensures complete consumption of the acid and
I had no problems with excessive oxidation or hydrolysis in the concentrated solution that results but evaporating it to crystallization was
difficult. I wonder if you could bring about crystallization by adding ethanol to the concentrated solution?
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yobbo II
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Some stuff here
https://geocitieschloratesite.000webhostapp.com/chlorate/mno...
Since I obtained 500 mls of nitric acid (at great expense) a few weeks ago. I have now made some Mn Nitrate by reacting it with pottery grade Mn
Carbonate and filtering. You need to leave the solution slightly acidic otherwise the Mn nitrate tends to decompose.
[Edited on 7-12-2017 by yobbo II]
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