Van der Waals’ affected by:
- Size of electron cloud
The size of the electron cloud is proportional to the molecular mass of the molecule, the larger the molecular mass, the larger the electron cloud and hence the stronger the VDW forces of attraction.
- Shape of molecule (branched vs linear)
For the same molecule C5H12, it can exist as either a branched or linear isomer. Due to the spherical nature of the branched isomer, there are less extensive VDW forces of attraction as indicated in the diagram above.
To determine the type of bonding in a simple molecular compound, we have to first determine if it is a polar or non-polar molecule.
A molecule is considered to be polar if it has a net dipole moment and that largely depends on the shape of the molecule.
Is there any reliable and easy way to determine the structural formula of a molecule? We will show you an extremely powerful method in our next post.