2.5: Chemistry Review
Intermolecular Forces – the forces between molecules and not within individual molecules
Van der Waals Forces (London Dispersion Forces) – are weak interactions between molecules caused by
momentary changed in electron density and are present in all molecules
Dipole-Dipole – the attractive forces between the permanent dipoles of two polar molecules, which
occur because the two molecules align their partial positive and partial negative charges into close
proximity. These are much stronger than Van der Waals Forces.
Hydrogen Bonding – the strong attractive forces between hydrogen and fluorine/oxygen/nitrogen. It
occurs because the very high partial positive charge on the hydrogen is attracted to a lone electron pair
on another molecule.
Boiling point – the temperature at which the vapour pressure of th