Which one shows maximum hydrogen bonding?
H2O show maximum hydrogen bonding because each H2O molecule is linked to four H2O molecules through hydrogen bonds. In each H2O molecule, the oxygen atom has two lone pairs (non-bonding electron pairs), each of which can form a hydrogen bond with a hydrogen atom from another molecule. Within the H2O molecule, the hydrogen atoms can each form a hydrogen bond with an oxygen atom ('s lone pair) from another H2O molecule. Thus 4 hydrogen atoms per water molecule. HF forms the stronger hydrogen bond but it forms fewer!
The other molecules do not exhibit appreciable hydrogen bonding.