What type of intermolecular force of attraction is found in CO2?

1 Answer

The only intermolecular forces present in CO2 are Van der Waals .

There are three kinds of intermolecular forces, so we need to consider each in turn and decide whether these are present in carbon dioxide.

The weakest kind are Van der Waals forces , caused by the instantaneous dipoles arising from random movements of electrons, attracting other molecules by inducing similar dipoles in them. All atoms and molecules have Van der Waals forces, so these are present in #CO_2#.

The next strongest are permanent dipole-dipole interactions, which are present between polar molecules. To be a polar molecule we have to have polar bonds (caused by a difference in electronegativity between the bonded atoms) AND we have to have these polar bonds NOT symmetrically opposed to one another so the dipoles arising from the polar bonds don't cancel each other out. #CO_2# has polar bonds (O is much more electronegative than C) but the polar bonds ARE symmetrically opposite to one another so #CO_2# is not a polar molecule and does not have permanent dipole-dipole interactions.

The strongest type of intermolecular forces are called hydrogen bonds. For these we need hydrogen atoms bonded to one of the three most electronegative atoms (N, O or F) so that the hydrogen atom has a partial positive charge, and we need a lone pair available on the electronegative atom. #CO_2# has no H atoms, so no hydrogen bonds.