What are some common mistakes students make with Van der Waals forces?
Van der Waals forces are also known as London Dispersion Forces.
It's important to realize that all molecules have slight Van der Waals forces in them. It's also the weakest bond so it's easy for it to break apart.
It's also important to recognize the difference between intermolecular forces and intramolecular forces.
While the hydrogen bonding in water is intermolecular, the covalent bond between the hydrogen and oxygen is intramolecular.
The two different types of bonding affect the molecule(s) in entirely different ways.