Question

Which of the following has the strongest H-bond ?

• A. $O - H...S$
• B. $S - H...O$
• C. $F - H...F$
• D. $F - H...O$

Answer 1

Answer: (C)

$F - H...F$

Answer 2

The strongest $H$ -bond is $F - H \ldots \ldots$ because in this case, a hydrogen is bonded to a most electronegative atom i.e. fluorine. In all other options, hydrogen is bonded to oxygen and sulphur that are less electronegative atom than fluorine.

The correct electronegativity order of elements are as follows: $F > \,O >\, S$