1. Intermolecular hydrogen bonding

1. Intermolecular hydrogen bonding raises boiling points and frequently melting
points.
2. If hydrogen bonding is possible between solute and solvent, this greatly
increases solubility and often results in large or even infinite solubility where
none would otherwise be expected.
3. Hydrogen bonding causes lack of ideality in gas and solution laws.
4. As previously mentioned, hydrogen bonding changes spectral absorption
positions.
5. Hydrogen bonding, especially the intramolecular variety, changes many
chemical properties. For example, it is responsible for the large amount of
enol present in certain tautomeric equilibria (see p. 98). Also, by influencing
the conformation of molecules (see Chapter 4), it often plays a significant role
in determining reaction rates.43 Hydrogen bonding is also important in
maintaining the 3D structures of protein and nucleic acid molecules.