Question

Which one of the following reactions proceeds through free radical chain mechanism?

• A. Addition of $HBr$ on ethene
• B. Halogenation of benzene in the presence of $FeBr_3$
• C. Photochemical chlorination of methane
• D. Hydrolysis of tert-butyl chloride with aqueous $KOH$
• E. Addition of $NaHSO_3$ on acetone

Answer 1

Answer: (C)

	Reaction	Mechanism followed
a	Addition of HBr on ethene	Ionic addition reaction
b	alogenation of benzene in the presence of FeBr $_{3}$	Electrophilic substitution reaction
c	Photochemical chlorination of methane	Free radical substitution
d	Hydrolysis of tert-butylchloride with aq. KOH	Nucleophilic substitution
e	Addition of $NaHSO _{3}$ on acetone	Nucleophilic addition

Thus, photochemical chlorination of methane proceeds via free radical chain mechanism.