Question

What is the vsepr model for CO2?

Answer 1

We can use VESPR theory to predict a linear shape for the molecule `CO_2` because of its `AX_2` status.

VESPR stands for valence shell electron pair repulsion. This theory basically says that bonding and non-bonding electron pairs of the central atom in a molecule will repel (push away from) each other in three dimensional space and this gives the molecules their shape.
We can use the following notations when examining a Lewis structure of a molecule.

A = central atom
X = peripheral atoms
E = non-bonding electron pairs of the central atom

`AX_2` = linear molecule
`AX_3` = trigonal planar
`AX_3E` = trigonal pyrimidal
`AX_2E_2` = bent
`AX_4` = tetrahedral molecule