Why is the Lewis structure of ozone important?

Jun 6, 2016

Why? Because it's a simple predictor of molecular shape.

Explanation:

The ozone molecule is ${O}_{3}$, and each $O$ centre contributes 6 electrons to the valence shell.

A reasonable Lewis structure would be: $O = {O}^{+} - {O}^{-}$. Because, around the central oxygen, there are 5 electrons (2 from the double bond, 1 from the single bond, and 2 from the lone pair), we assign this centre a positive charge, and of course we can assign each terminal oxygen a negative charge alternately by resonance.

Given the Lewis structure we predict by $V S E P R$ a bent molecule with $\angle O - O - O$ $\le$ 120""^@. What do we find experimentally? A bent molecule with intermediate $O - O$ bonds; $\angle O - O - O$ $=$ 116.8""^@.

Thus, by simply knowing how to draw a Lewis structure, counting the electrons, and using $V S E P R$, we have predicted the structure of a gaseous molecule, which we can't see, but we can smell. I think that is pretty clever given the (short!) time we spent on the problem.