Alkanols have unexpectedly high boiling points relative to their molar masses because of intermolecular

Alkanols, also known as alcohols, have unexpectedly high boiling points relative to their molar masses because of intermolecular hydrogen bonding. Hydrogen bonding is a type of intermolecular force that occurs when a hydrogen atom bonded to an electronegative atom, such as oxygen or nitrogen, is attracted to another electronegative atom in a nearby molecule. In the case of alkanols, the hydrogen atom attached to the oxygen atom in one molecule can form a hydrogen bond with the oxygen atom of another molecule. This results in a network of intermolecular hydrogen bonds that are much stronger than the weak van der Waals' forces that exist between non-polar molecules of similar size and shape. Due to the presence of these strong intermolecular forces, more thermal energy is required to overcome these forces and cause the molecules to separate, resulting in higher boiling points of alkanols relative to other organic compounds of similar molar mass.