Most of it was said by Jeff's recommended article. Let me add a few info
taken from my experience and my chemical dictionary.
By dissolving CuCo3 in HCl solution, you almost for sure got CuCl2. That is
how I prepare my CuCl2. The solution will vary widely in color (blue,
green, almost opaque green-brown) depending the concentrations of the
various compounds in solution, as mentioned in the article recommended by
Jeff. If you boil the solution and let it evaporate, you will get green
crystals that will turn brown at 100°C if completely dehydrated. CuCl2 =
yellow-brown, CuCl2.2H2O =green.
I have contacted Cu with HCl solution and boiled it a long time ago. After
several days, I got a green solution. CuCl or CuCl2? That is the question,
although the color would suggest CuCl2. From my chem. dictionary, one
obtains CuCl (white cubical crystals, slightly soluble in water, becomes
greenish on exosure to air) by contacting Cu with CuCl2 or Cu with HCl in
air. CuCl is soluble in acids, ammonia, ether, etc., though. My guess
would be that contacting HCl with Cu (especially with an excess Cu) will
give some sort of mixture of CuCl and CuCl2, but that is just a guess.
By the way, you can also obtain CuCl by heating CuCl2 at 985°C (which is
what would happen in a pyrotechnic composition, except that CuCl2 is
unactractive due to its water absorption property).
Solubility of CuCl2.2H2O: 77 g/100 g H2O at 20°C, 107.9 g/100 g H2O at
Solubility of CuCl: 1.52 g/100 g H2O at 25°C.
Copper oxychloride is said to be insoluble.
But then, what you are really interested is copper oxychloride, and the
article recommended by Jeff will tell more than what I can even master.
I will have to try to make copper oxychloride myself in the coming weeks, I
wonder if air could not be replaced with hydrogen peroxyde in the reactions
calling for bubbling air...
Post by Bas
I'm trying to make copper oxychloride. I read somewhere that it can be made
by dissolving copper in hydrochloric acid (takes a while..) and after that
pumping air through the solution.
First I've tried to solve thin pieces of copper in HCl, which gives a (nice)
green solution, but it took days.
So I thought that dissolving copper carbonate (CuCO3?) in HCl would go MUCH
faster. It dissolved indeed much faster (and gas came free, I suppose CO2).
But.. the solution is blue..(looks like CuSO4 solution, maybe somewhat less
I don't understand. I thought in both cases I would get CuCl2, but why then
the difference in color??
Bas from Holland