Which of the following sequences accurately represents the increasing order of bond dissociation ent — Chemical Bonding Chemistry Question

💡 Solution & Explanation

Generally, bond dissociation enthalpy decreases as atomic size increases. However, $F_2$ exhibits an exceptionally low bond dissociation energy (lower than $Cl_2$ and $Br_2$) due to immense inter-electronic repulsions between the lone pairs localized on the very small fluorine atoms. Thus, the order is $I_2 < F_2 < Br_2 < Cl_2$.