morsagh - 15-8-2015 at 12:45
I dissolved some ascorbic acid in vinegar, added solution of KMnO4 and NaOH solution to precipitate Mn(OH)2, but solution just
turned yellow and then on air nice cherry-red. What is my product? I expected MnO2 or Mn(OH)2.
photo
morsagh - 15-8-2015 at 12:47
photo of my product
aga - 15-8-2015 at 13:18
Who can say with that mix ?
Things like which isomer of ascorbic acid, how much, what vinegar, what % what volume, how much KMnO4, how much NaOH, how much Water -
these all really need to be measured and Known before just mixing stuff up.
There's no way to accurately give any sensible answer otherwise.
Looks like pot permanganate colour to me.
Please put questions like this in the Beginning thread.
[Edited on 15-8-2015 by aga]
[Edited on 15-8-2015 by aga]
blogfast25 - 15-8-2015 at 13:59
Looks to me you didn't add enough ascorbic acid to reduce all permanganate and not enough NaOH to neutralise all acid.
Try and work quantitatively, not just mix unknown quantities.
Texium - 15-8-2015 at 14:01
aga overexaggerates the level of uncertainty. That color is commonly seen when reducing permanganate. It is likely caused by a suspension of fine
particles of MnO2 in excess permanganate. Let it settle out for a day and you should see it separate. If not, it could be due to Mn(III) which is red,
but that is less likely, particularly since it is only stable in acidic conditions.
[Edited on 8-15-2015 by zts16]
unionised - 16-8-2015 at 00:32
I suspect an ascorbate complex of Mn(II) or possibly Mn(III).
Of course there's always the possibility that it's more or less caramelised ascorbic acid.