6.4 Hydrogen bonding

• Hydrogen bonds are the strongest intermolecular force
• Hydrogen bonds occur between

  • an H atom bonded to an electronegative atom in one molecule
  • a lone pair of electrons on an electronegative element in a different molecule
• Ice is less dense than water because the water molecules are held in an open lattice structure by the hydrogen bonds
• Water has a much higher melting/boiling point than expected because the hydrogen bonds are the strongest intermolecular force
• Simple molecular substances tend to have relatively low melting points because of the weak intermolecular forces
• Simple molecules are poor electrical conductors because they don't have a charge
• Simple molecules have weak dipoles and tend to be soluble in non-polar solvents and insoluble in water