Question

Which of the following has the highest bond energy ?

• A. Fluorine
• B. Bromine
• C. Iodine
• D. Chlorine

Answer 1

Answer: (D)

Chlorine

Answer 2

Bond energy of Fluorine (although $F_2$ has smallest bond length) is lesser than $Cl_2$ and $Br_2$ due to greater interelectronic repulsions between the lone pair of electrons on F atom. Halogen F - F Cl - Cl Br - Br I - I Bond dissociation 38 57 45.5 35.5 energy (kcal/mol) So chlorine has highest bond energy.