Hydrogen Bonding - Second Year Chemistry Topic

Hydrogen bonding is said to be formed when slightly acidic hydrogen attached to a strongly electronegativity atom such as F, O and N is held with weak electrostatic forces by the non-bonded pair of electrons of another atom. That is, it is a dipole-dipole interaction.

• Of all the electronegative donor atoms, only F, O and N enter into stable H-bond formation.
• Greater the electronegativity difference between the bonded atoms, stronger is the Hydrogen bonding.

For example: The electronegativity difference between F and H is greater than that of between Cl and H, therefore HF is more polar than HCl.

Intramolecular Hydrogen bonding: This type of Hydrogen bonding occurs between polar H and electronegative atom present in the same molecule.

Intermolecular Hydrogen Bonding: This type of Hydrogen bonding takes place between hydrogen and electronegative element present in the different molecules of the same substance (H2O and H2O) or different substances (H2O and NH3).