Looks like it does have different colours depending on if its anhydrous etc. The dark blue crystals are really pretty, i also like the ones on copper
wire, anyway read the wiki article linked it might help.
[Edited on 13-9-2016 by NEMO-Chemistry]ficolas - 13-9-2016 at 13:18
And you may have light blue impurities (copper hidroxide) in the one you boiled, as there is an equilibrium reaction that shifts to the copper
hidroxide with heat.
A better explanation can be found here http://www.sciencemadness.org/talk/viewthread.php?tid=66247#...
Where I asked another things about copper acetate.
The green crystals ended up being caused by chlorine contamination (in my case) from tap water because I didnt have dH2O then.Fidelmios - 13-9-2016 at 13:57
Is there a way to separate the Copper Hydroxides out? I sorta made a large batch and don't want to waste 500g of Copper Acetate ficolas - 13-9-2016 at 14:12
Yes.
The reaction is this one:
Cu(CH3COO )2 + 2H2O+ <-> Cu(OH)2 + 2CH3COOH
So by increasing the amount of acetic acid, you shift the equilibrium to the left. Heat favors the endotermic reaction (formation of Cu(OH)2, do you
need to keep the solution cold.
What you can do, is instead of boiling the solution, letting it evaporate. I think you would need to use acetic anhydride or distill the water off to
keep the conditions of the solution always acidic enough for copper hydroxide to not form if you want to boil it. And if you use acetyc anhydride,
well distill it, boiling is wasteful (and dangerous too, probably?)
Another thing you can do, is recrystalyce it. Copper hydroxide is insoluble, so dissolve the copper acetate in the smallest amount of (normal
temperature) water possible (sloooow additions of water at the end!), then filter of the insoluble copper hydroxide, cool it down, and filter your
copper acetate precipitate. This will remove other impurities your product may have, at the cost of loosing a bit of copper acetate. I would use
acetic acid to do the recrystalization, as this will allow the copper hydroxide to be turned back into copper acetate.
I cant ensure you that the recrystalization will work, since you cant use how water because that would make more copper hydroxide (unless you use
acetic anhydride?), and I am not the best person in the forum to give you advice, this is what I know from experience of messing arround with copper
acetate, but my knowledge about chemistry isnt that great. So if im wrong in any aspect of the repply, im sure somebody will correct me
All in all, the easiest way is dissolving everything in cold acetic acid, an letting it evaporate without heat, easy but slow.
[Edited on 13-9-2016 by ficolas]
[Edited on 14-9-2016 by ficolas]Texium - 13-9-2016 at 16:00
