Tiago Gomes - 23-11-2004 at 06:56
hi, do you know how to get rid of the water molecules in copper(II) acetate monohidrate. melting point 115ºC
Boiling Point:
240C (464F) Decomposes.
Mephisto - 23-11-2004 at 07:20
Huh, so what's the problem? The monohydrate will lose it's crystal-water completely at 100°C. Even if you can't regulate the
temperature and heat till it melts, you can repulverize your melt again.
chemoleo - 23-11-2004 at 07:52
Alternatively, make a superstrong solution of the acetate, and poor that into a large excess of ethanol.
The water-free salt should precipitate (somewhere I have done this, but I don't know if it will work in this particular case. It depends of
course how tightly the H2Os are coordinated.)
Tiago Gomes - 23-11-2004 at 08:17
but is there like cu(II) acetate with 2 molecules of water or more?
vulture - 23-11-2004 at 08:50
You're a post doc and you're struggled by stuff like this???
Tiago Gomes - 23-11-2004 at 08:56
aha good one
i´m just posting topics i dont need it for anything
it´s not a doubt just a thread, simple things....maybe anyone could find an creative solution and not reading it in books, like a recipie.
vulture - 23-11-2004 at 09:00
If you're just posting topics for the heck of it, please check if such thing hasn't been discussed before.
And this technique has been discussed many times before, as it is invaluable for isolation of inorganic salts.
chemoleo - 23-11-2004 at 09:06
Not just that... I often noticed people who post 'for the heck of it' either 1) want an FTP account 2) are drunk or bored 3) have some
attention seeking syndrome.
Rarely, unfortunately, this translates into a good topic/post.
A genuine interest is usually a better recipy for a good topic/post.
Not intended as a flame (I guess it's been enough for one day 
), but yet
something that struck me as relevant enough to make it worth mentioning....
[Edited on 23-11-2004 by chemoleo]
Tiago Gomes - 23-11-2004 at 09:21
yeah my case was the first one , but i tried to put +/- challenging things. in the case of copper acetate its not that trivial to heat it up or to
make a strong solution,thera are other things to take in consideration, like the orbital theory(this compound is a special case). and much more
dificult than what it seems, and the mechanism of loosing H2O isn´t very well explained.In teory it does not losses the H2O, but in common sense it
looses it.
i will make a resume of this for everyone to understand and post here in a few days (as soon as i´ve got time)
bye
[Edited on 23-11-2004 by Tiago Gomes]
vulture - 23-11-2004 at 09:45
Well if you would have included the fact that there is something special about the orbitals (or are you referring to crystal field theory?) and other
relevant stuff, then maybe we wouldn't be so irritated...
HINT
darkflame89 - 24-11-2004 at 00:41
Simple! If you just want to get rid of the water molecules, just add concentrated ammonia solution or concentrated hydrochloric acid to copper(II)
acetate. The water molecules as ligands are then replaced.
Your "complicated orbital theory"; do you mean ligands? The water molcules form ligands around the copper ion. So, you either simply drive
off the water with heat(there's no consideration of " orbital theory", or you replace yer ligands with other ligands, where the theory you mean refers to quantum theory.
JohnWW - 24-11-2004 at 09:53
I suspect that heating crystals of monohydrated Cu(II) acetate to the melting-point, 115ºC according to Perry, may result in at least partial
hydrolysis to Cu(OH)2 or CuO, with liberation of acetic acid vapor when its boiling-point of 118.1ºC is reached with further heating. The anhydrous
salt exists, however, but its melting and boiling-points are not given. Cu(II) acetate is supposed to decompose at 240ºC, but this is given for the
monohydrate, rather than the anhydrous salt.
TheBear - 25-11-2004 at 07:45
Heating of Cu(II)acetate gave me: lots of smoke with acetic acid odour, a nice cough and Cu2O (red solid).
It was heated in a copper retort which makes the reaction CuO + Cu ---> Cu2O a possibility (if CuO was expected).
unionised - 25-11-2004 at 14:13
Would it be just terribly dull to react it with acetic anhydride?
The acetic acid formed wouldn't (I guess) be as good a complexing agent and could be evaporated off. A desiccator with NaOH in might be a good
thing to have here.
chemoleo - 26-11-2004 at 05:27
Or how about 'CuO + (Ac)2O --> CuAc2 ?
No water ever involved.
Excess acetic acid can be distilled off.