Which of the following hydrogen bonds is the strongest?

The correct order of $H$-bond strength for the following interactions is:
$a: F^{-}H...F^{-}$
$b: F^{-}H...F$
$c: O^{-}H...N$
$d: O^{-}H...O$
Identify the correct order of strength.

Select the compound from the following which dissolves in water.

The correct order of boiling point in the following compounds is

The boiling point of glycerol is higher than that of propanol because of:

Hydrogen bond energy is equal to