[eRReR]

Hi all,

I was reviewing some notes on electronegativity differences and bond designation. I find that  :delta:EN of greater than 1.7 are ionic bonds and between 0.4 and 1.7 are polar covalent bonds.

With that, looking at the  :delta:EN in CuCl₂, you get 3.0-1.9=1.1. That suggests a polar covalent bond. Why is it, then, that when naming CuCl₂, we use an ionic naming scheme?

[bidiboom]

CuCl₂ is certainly an ionic compound, but the limits of the ionic/covalent desription is somewhat blur.. maybe because of this reason it misled you..

[eRReR]

So, I think I understand it a bit better now. The EN difference should only be used to discuss the extent to which the electrons are "shared" among the two bonded atoms. With larger EN differences, the bond displays more "ionic" character, meaning that there is a stronger polar bond. With smaller EN differences, the atoms (whether an ionic, e.g. CuCl2, or covalent compound, e.g. CCl4) display more "sharing" and a less polar bond.

So, CuCl2 (as initially expected) is an ionic compound, though the bonds are not as polar as something like LiF. Am I correct?