Define hydrogen bond and its types .

Answer

(i) Hydrogen bond:
When a hydrogen atom (H) is covalently bonded to a highly electronegative atom (F or O or N) , the bond is polarized in such a way that the hydrogen atom is able to form a weak bond (electrostatic attraction) between the hydrogen atom of a molecule and the electronegative atom a second molecule. The bond thus formed is called a hydrogen bond
(ii) Intermolecular Hydrogen:
Intermolecular hydrogen bonds occur between two separate molecules.
They can occur between any numbers of like or unlike molecules as long as hydrogen donors and acceptors are present an in positions in which they can interact. Eg: Water , HF, ect,.
(iii) Intramolecular Hydrogen:
This type of bond is formed between hydrogen atom and N, O or F atom of the same molecule. This type of hydrogen bonding is commonly called chelation and is more frequently found in organic compound . Eg:o-nitro phenol,salicylic acid, etc,.