Question

Bond dissociation energies of $HF,HCl$ and $HBr$ follows the order:

• A. $HCl>HBr>HF$
• B. $HF>HBr>HCl$
• C. $HF>HCl>HBr$
• D. $HBr>HCl>HF$

Answer 1

The correct option is C $HF>HCl>HBr$

There is a large difference between electronegativity of $H$ and $F$, so the bond is stronger. As we go down the group, the difference between electronegativity decreases and therefore, bond dissociation energy also decreases.

The order of bond dissociation energies are $H-F>H-Cl>H-Br$.

Option C is correct.