Lion850
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Formula for dark green chromium acetate
I received a chemical labelled only "chromium acetate". Still in the original suppliers bottle but I think it is quite old. Initially I thought it was
black crystals in the (full) bottle but in sunlight it seems a very dark green. It is sparingly soluble in water at room temperature, a concentrated
solution is dark green and it becomes more brighter green as the solution is diluted. The lid has a slight vinegar smell. Photos of the crystals and
the concentrated solution attached.
My question is, what is the likely formula? From the internet is seems the only dark green acetate of chromium is "Chromium acetate hydroxide
Cr3(OH)2(OOCCH3)7". I'm sure there will be members experienced with chromium salts and I would appreciate opinions whether it is likely the acetate
hydroxide or whether their is another dark green acetate of chromium that I don't know about.
 
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Fery
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Wow you've bought a chemical compound from a supplier who is even unable to label the bottle properly.
It seems to be chromium (III) acetate.
Chromium (II) acetate is red and almost insoluble in water.
[Edited on 10-1-2020 by Fery]
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Lion850
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Quote: Originally posted by Fery  | Wow you've bought a chemical compound from a supplier who is even unable to label the bottle properly.
It seems to be chromium (III) acetate.
Chromium (II) acetate is red and almost insoluble in water.
[Edited on 10-1-2020 by Fery] |
Just for the record, I went to buy something else and then the (still sealed) old stock jar of "chromium acetate" was mentioned. I think this bottle
is from the days when labelling requirements were much less stringent. The supplier was 100% certain is was an acetate of chromium (as it says on the
label) but at the same time he pointed out that it was not detailed on the label exactly which acetate or acetate hydrate. I made the decision to take
it as it was basically free 
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DraconicAcid
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It's obviously chromium(III) acetate- if it was a rarer oxidation state, they would have specified. Since Aldrich and Fischer only sell the basic
form, that's probably the only form stable enough to sell in bulk.
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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