High boiling point is primarily caused by strong intermolecular forces, particularly hydrogen bonding which is the main reason for water's high boiling point, as water molecules can form multiple hydrogen bonds with each other, requiring more energy to separate them and vapourize. Consequently, water, ethanol and aquous sodium chloride would have relatively high boiling points, owing to the presence of hydrogen bonds while tetrachloromethane has no hydrogen bonding, hence, it is has the lowest boiling point.