Question

Which one of the following cleavage leads to generation of free radical?

• A. Homolytic cleavage
• B. Heterolytic cleavage
• C. Both (a) and (b)
• D. None of the above

Answer 1

The correct option is A Homolytic cleavage

Bond breaking is of two types. One is homolytic cleavage and other is heterolytic cleavage. In homolytic cleavage, one of the
electrons of the shared pair in a covalent bond goes with each of the bonded atoms. In heterolytic cleavage, the bond breaks in such a fashion that the shared pair of electrons remains with one of the fragments. So the correct answer will be option(a). For example, when light is incident on $C{H}_3-Cl$ it undergoes into $\stackrel{\bullet }{C}{H}_3$ and $\stackrel{\bullet }{C}l$.
$C-Cl\underset{\text{bond fission}}{\overset{Homolytic}{\to }}\underset{\text{free~radical}}{\stackrel{\bullet }{C}}+\underset{\text{free~radical}}{\stackrel{\bullet }{C}l}|$
An atom, molecule or ion with an unpaired electron in its valence shell is called a free radical.