guy - 31-12-2004 at 01:19
I'm doning electrolysis of copper electrodes in MgSO4 solution with a salt bridge. Copper sulfate is being produced but it also has MgSO4. How
can I separate the two?
hodges - 31-12-2004 at 14:32
What I did was use a membrane between the two electrode. In my case I used two dishes with a wet paper towel connecting them. I calculated how much
electricity would need to flow to take all the Mg ions to the cathode and then let it run a bit longer than that (I had to replace the cathode
solution several times because the MgOH formed does not conduct well, but this did not affect the anode side). When I evaporated the solution I still
had some MgSO4 though - presumably because the solutions mix somewhat through the paper towel. Not sure how to do better than this.
HNO3 - 31-12-2004 at 15:08
Fractional crystalization. The CuSO4 will be the blue crystals. Otherwise, you might try mixing it with alcohol, to precipitate the CuSO4, but
I'm not sure about this.
guy - 31-12-2004 at 15:45
The only alcohol I have is isopropyl (99%). The internet doesn't have much on solubility of salts in this alcohol. When I added the copper
sulfate and magnesium sulfate solution, it started crystallizing.
[Edited on 1/1/2005 by guy]
Crystallizing out MgSO4
guy - 31-12-2004 at 16:08
Would only the MgSO4 crystallize out if I place a seed crystal of MgSO4 in the solution and leaving behind only CuSO4?
How long would this take?
Thanks
HNO3 - 31-12-2004 at 17:12
Do you have methanol or glycerol to spare? Methanol can be gotten from Heet(r). CuSO4 is only soluble in methanol and glycerol, but MgSO4 is only
slightly soluble in them. Then evaporate the solution.
guy - 1-1-2005 at 01:30
Just wondering...
Will the magnesium hydroxide produced be equal to 1/7 of the magnesium sulfate heptahydrate produced?
HNO3 - 1-1-2005 at 12:35
I don't think any magnesium hydroxide eill form. If you have a sopper sulfate seed crystal, the CuSO4 might crystalize out though. All my copper
salt solutions have slowly crystalized out on their own.
guy - 1-1-2005 at 14:09
No.... I mean in the cathode side were hydrogen is produced.
HNO3 - 1-1-2005 at 14:56
Oh. I don't know.