Ions in a solution

[jowrose]

Is there any way to get only the ions of a metal into a solution? Say you have a solution of CuCl2. Is there a way to remove the chloride ions, leaving aqueous Cu2+ without reducing the copper to copper metal?

[woelen]

No, this is not possible. Imagine such a solution with H2O and Cu(2+) ions in it with no counter anion like chloride. It would be an extremely highly charged liquid, which would explode at once, due to the strong repelling electrostatic forces. Any macroscopic chemical compound, whether it is pure, a mix, a solution, whatever, is electrically neutral.

[sunspot]

If one used a modified ion exchange resin it might be possible. The modification would tie up the chloride without release anything. I did something similar for a mercury removal innovation. I began with an anion exchange resin and treated it with sulfide. It now becomes a cation exhange resin with sulfide active sites. These react with the dissolved mercury to fix it as mercury sulfide, on the ion exchange back-bone. In this case, chloride becomes fixed so when we remove the resin cations are left.

 

Another way may be to use two electrodes to segregate the ions. Then put a membrane bridge down in the middle and reverse the polarity to free the ions. The two connected compartments should balance the charge. Next, add a partitian that is nonconducting. These are only speculation, but these would be my first prototypes.

[woelen]

Of course you can separate small quantities of charge (capacitors also do that), but these are small when expressed in terms of moles. E.g. a 1 F capacitor, which holds 1 Coulomb of charge at 1 V is HUGE in terms of electronics, but still in terms of moles it is tiny: 1 C of charge is only appr. 0.00001 mole of electrons. Electronics capacitors usually are expressed in μF or nF.

 

I still think that e.g. 1 mole of copper ions in a liter of water, would be an extremely unstable thing and would explode, because of the repelling electrostatic forces.

[Bluenoise]

Don't forget about charge gradients created across biological membranes.

 

The typical NA+ K+ ion pump is able to create a charge potential by swapping 3 Na+ ions for 2 K+ ions.

 

Not to mention the Many H+ gradients.