Understanding Ligand Strength: [Cu(H2O)6]2+ to [CuCl4]2-

[AryaUnderfoot]

Homework Statement

From what I've read, [Cu(H₂O)₆]²⁺ when reacts with concentrated hydrochloric acid, the chloro ligand will displace the aqua ligand and form [CuCl₄]^2-

Homework Equations

[Cu(H₂O)₆]²⁺ + 4Cl^- <--> [CuCl₄]^2- + 6H₂O
( <---> means reversible reaction, I don't know how to type it out, sorry)

The Attempt at a Solution

But chloro is a weaker ligand than aqua, how can the ligand substitution reaction happen?

 

[PWiz]

I suspect the high concentration of the Cl- ions is sufficient to shift the equilibrium over to the right (Le Chatelier's principle) enough to cause a majority of the complex ions to undergo the ligand substitution.

 

[Borek]

Water concentration is (almost) always much higher.

It is not just about the ligands, you are ignoring change of the geometry. Not that I know it is the answer here - I just see you are not taking it into account.

 

[AryaUnderfoot]

I also like to ask, since no one comment about that, is water a ligand or aqua? I know that both refer to H₂O, but if I want to mention a ligand, which one of them, aqua/aqua ligand/water/water ligand, is more appropriate?