Question

Arrange the following bonds according to their average bond energies in descending order.

$C-\text{Cl},\text{ C}-\text{Br},\text{ C}-F,\text{ C}-I$

• A. $C-F>C-\text{Cl}>C-\text{Br}>C-I$
• B. $C-I>C-\text{Br}>C-\text{Cl}>C-F$
• C. $C-\text{Br}>C-I>C-\text{Cl}>C-F$
• D. $C-\text{Cl}>C-\text{Br}>C-I>C-F$

Answer 1

Answer: (A)

$\text{Bond} \, \text{energy} \propto \frac{1}{\text{Bond length}}$

As on moving down the group size increases so bond length increases hence bond energy decreases.

Bond energy $C-F>C-\text{Cl}>C-\text{Br}>C-I$