It is an electrostatic attractive force between hydrogen of one molecule or part of an molecule and an electronegative atom ( F, O, N ) of another molecule (intermolecular ) or another part of same molecule ( intramolecule )
Hydrogen Bonding -
Attractive force which binds hydrogen atom of one molecule with the electronegative ( F, O, N ) atom of another molecule.
It is of two type
1. Intermolecular and
Strenght of Hydrogen bond -
Electrostatic force > covalent bond > H bond > Vander Wall's force
H bond is a very weak bond and its strength is intermediate between the weak Vander wall force and strong covalent force.
B.P. order is
due to hydrogen bonding in , it has high B.P. then other halides.