Explain different types of hydrogen bonds with examples.

Explanation

The concept of H - bond is due to Huggins , Latimer and Rodebush.
Def : " The electrostatic force of attraction between a partially changed hydrogen atom of a molecule and a highly electronegative atom of the same molecule or different molecule is known as, H - bond."
Explanation :
1) The molecule having H - bonds should have a highly electronegative atom like F, O or N directly linked to H - atom by a covalent bond .
2) H - bond is stronger than van der Wall.s forces but weaker than ionic and covalent bonds.
Van der waal.s forces `lt` H - bond
Energy : `2-10 "kJ mol"^(-1) 2-40 "kJ mol"^(-1)`
`lt` Covalent bond `lt` lonic bond
`200-400 "kJ mol"^(-1)`
3) The strength of H - bond increases with the EN of the atom attached covalently to H atom.
Type of H - bonds : `2` types. 1) Intramolecular H - bonding and 2) Inter - molecular H - bonding
1) Intramolecular H - bonding : The H - bonding formed between H atom of a molecule and a highly electronegative atom of the same molecule, is called intramolecular hydrogen bond.
Ex :
2) Inter molecular H - bonding : The H - bonding formed in between H - atom of one molecule and a highly electronegative atom of another molecule of same substance or different substances is called intermolecular hydrogen bond.

Consequences of H - bonding :
1) Highly viscous nature of `H_(2)SO_(4), NHO_(3), H_(3)PO_(4)` etc is due to H - bonding.
2) The high b.p. of water is due to H - bonds in it.
3) `H_(2)O` is a liquid but `H_(2)S` is a gas, since H - bond is present in `H_(2)O` only