Question

The order of strength of hydrogen bond is:

• A. $N-H\cdots N>O-H\cdots O>F-H\cdots F$
• B. $N-H\cdots N>O-H\cdots O>F-H\cdots F$
• C. $O-H\cdots O>N-H\cdots N>F-H\cdots F$
• D. $F-H\cdots F>O-H\cdots O>N-H\cdots N$

Answer 1

The correct option is D $F-H\cdots F>O-H\cdots O>N-H\cdots N$

Hydrogen bond strength increases with the increase in the electronegativity diiference between the hydrogen atom and the other bonded atom.
The Eelectronegativity of $F,O,N$ follows the order $F>O>N$
So the correct order of strength of hydrogen bond would be,
$F-H\cdots F>O-H\cdots O>N-H\cdots N$