[ccccc]

Hello. I am currently working on an essay investigating the hard/softness of the Copper(II), in which I am planning on reacting the copper ion with some of the halides and compare the stability constant. In studying the subject I have however come across two questions which are probably very basic and are thus not explained in the covering literature (or I have just not understood it properly).

1) When the cation is hydrated and surrounded by water molecules, why would halide ligands necessarily replace the water ligands? For example, 1 mole of cation exists in excess H2O and as far as I understand it, when 1 mole of Cl- ion is added (in the form of HCl for example) the Cl- ion acts as a ligand and unconditionally replaces a water molecule (in the proportion dictated by the equilibrium constant). Is this correct? How much water is the displaced as the initial coordination number was 6.

2) For preparation of the Cu2+ ion for reacting with the halide ligand ions, what method is recommended using reasonably common stock?

Thank you very much for your time