bigtrevs98
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contaminated sodium hypochlorite?
So I made some manganese chloride and had already finished up with that. Washed out my stuff and started on another project. (Trying to freeze distill
bleach) and I put some of my (what I hope to be but still haven't looked yet) more concentrated sodium hypochlorite in a container that contained the
manganese chloride. The solution of sodium hypochlorite immediately turned a dark red/amber color. I'm guessing I didn't quite wash my container
enough. But could anyone tell me what happened? I can upload pics if needed
[Edited on 8-5-2015 by bigtrevs98]
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blogfast25
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Quote: Originally posted by bigtrevs98  | So I made some manganese chloride and had already finished up with that. Washed out my stuff and started on another project. (Trying to freeze distill
bleach) and I put some of my (what I hope to be but still haven't looked yet) more concentrated sodium hypochlorite in a container that contained the
manganese chloride. The solution of sodium hypochlorite immediately turned a dark red/amber color. I'm guessing I didn't quite wash my container
enough. But could anyone tell me what happened? I can upload pics if needed
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Yup. Small amounts of sodium permanganate were formed.
NaClO is one of the most powerful oxidisers around. It's capable of kicking Mn(+2) to Mn(+7). But don't get optimistic about preparing permanganates
that way: due to the intense colour of the MnO<sub>4</sub><sup>-</sup> anion it always looks a lot but is quite a little only.
[Edited on 8-5-2015 by blogfast25]
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bigtrevs98
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Is the sodium permanganate from the manganese chloride or is it from the unreacted manganese dioxide?
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blogfast25
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It doesn't really matter. Bleach is alkaline. So with MnCl2, Mn(OH)2 is first formed, then oxidised to MnO2, then to permanganate.
First hand experience, BTW.
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bigtrevs98
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Ah okay. Great thanks 
Edit: quick question. I thought sodium permanganate was purple? Why is it reddish?
[Edited on 8-5-2015 by bigtrevs98]
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gboneu
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A cleaning mixture you can use that helps cleaning Manganese Oxides is Oxalic acid in dilute hydrochloric acid
I've used it and it works fine in case you have the precipitate stuck to the walls of any glass vessel
Usually permanganate is purple, but in acidic solutions are sometimes red.But it's a posbility, maybe another contaminants are present.
[Edited on 13-5-2015 by gboneu]
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blogfast25
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Low concentration. Colour of solutions goes from light pink, to reddish to purple to almost black.
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AJKOER
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Just was reading a source that noted adding CuCl2 to alkaline NaOCl will act as a catalyst in making the MnO4- anion. To quote:
"Dixon and White (2) examined the conversion of Mn(Il) to permanganate by hypochlorite, and noted that copper could catalyze this."
Reference: "DECOMPOSITION OF SODIUM HYPOCHLORITE : THE CATALYZED REACTION", by M.W. Lester, published in the Canadian Journal of Chemistry, volume 34,
1954. The Dixon & White reference refers to the J. Chem. Soc., #1469, 1927.
[Edited on 3-6-2016 by AJKOER]
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