MnCl2 won't dissolve?

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tummo1997
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MnCl2 won't dissolve?

Post by tummo1997 »

Hi all,

I am trying to dissolve 2g of anhydrous MnCl2 (pale pink powder/flakes) in 70ml demineralized water at room temperature with moderate manual stirring. Although solubility at RT is supposed to be high, I could not obtain the desired solution yet. All I am getting is a bright-brownish solution, from which, after resting for several hours, a very fine bright-brownish precipitate/fog settles. The remainder of the solution is visually clear and has a pH of roughly 6..7 according to an indicator paper strip.

I did some research on the WWW and all I came up with is that MnCl2 solution should be pale pink, while the colour I am observing rather hints at MnO(OH) as a result of Mn2+ oxidation.

Any ideas what the problem could be (aside from the one in front of the keyboard)?


Cheers,
T.
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ChenBeier
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Re: MnCl2 won't dissolve?

Post by ChenBeier »

How is the demineralzed water made. Maybe organic from manufacturing inside. Use destilled water instead. Add 1 ml HCl to get pH of 5 to 6.
Or the crued product contain oxidiser substances.
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