Question

Which of the following is a free radical substitution reaction ?

• A. Benzene with $Br_{2} /AlCl_{3}$
• B. Acetylene with $HBr$
• C. Methane with $Br_{2}/hv$
• D. Propene with $HBr/(C_{6}H_{5}COO)_{2}$

Answer 1

Answer: (C)

$HC\equiv CH \ce{ ->[HBr] }\underset{\text{(Electrophilic addition)}}{{CH_{2}=CH-Br}}$
$CH_{4}+Br_{2} \ce{ ->[hv] }\underset{\text{(Free radical substitution)}}{{CH_{3}-Br+HBr}}$
$CH_{3}-CH=CH_{2}+HBr \ce{ ->[(C_{6}H_{5}COO)_{2}] }$