Definition: It is defined as the electrostatic force of attraction which exists between the covalently bonded hydrogen atom of one molecule and the electronegative atom other molecule.
Cause: An electrostatic force of attraction between hydrogen atom of one molecule and electronegative atom of second molecule.
Condition:
(1) Hydrogen atom should be connected to highly electronegative atom say F, O or N.
(2) The electronegative atoms should be small in size.
Strength: It is a very weak bond, weaker then ionic and covalent bond.
Types of H-Bonding: There are two types of hydrogen bounds.
(i) Intermolecular hydrogen bond: It is formed between two different molecules of the same or different compounds. For example, H-bond in case of HF, alcohol and water. H − F……... H − F……...H − F……… (Intermolecular) H-bond in HF molecule)
(ii) Intramolecular hydrogen bond: It is formed when hydrogen atom is in between the two highly electronegative (F, O, N) atoms present within the same molecule. For example, in o- nitrophenol the hydrogen is in between the two oxygen atoms.
(Intramolecular hydrogen bonding in o-nitrophenol molecule)
