Question

The correct order of bond dissociation enthalpy of halogens is :

• A. $Cl _{2}> F _{2}> Br _{2}> I _{2}$
• B. $I _{2}> Br _{2}> Cl _{2}> F _{2}$
• C. $Cl _{2}> Br _{2}> F _{2}> I _{2}$
• D. $F _{2}> Cl _{2}> Br _{2}> I _{2}$

Answer 1

Answer: (C)

$Cl _{2}> Br _{2}> F _{2}> I _{2}$

Answer 2

Correct order of bond dissociation enthalpy of halogens is $Cl _{2}> Br _{2}> F _{2}> I _{2}$.

Due to inter electronic repulsions $F - F$ bond becomes weak and easily broken.