Question

Which of the following cleavage of bond can result in Homolytic Cleavage?

• A. $Cl-Cl$
• B. $C{H}_3-H$
• C. $C{H}_3-OH$
• D. $C{H}_3-COOH$

Answer 1

Answer: (A), (B)

$C{H}_3-H$

What do you mean by Homolytic Cleavage?

Homolytic Fission:

Occurs in gas phase or in non-polar solvents and is catalysed by reagents. In such fission free radicals are formed. Here the bond pair is equally shared after the fission.

$AB\to A^0+B^0$ (free radicals)

Condition for Homolytic Bond Fission : Homolysis takes place in the presence of peroxide, UV light, heat $(\ge {500}^{\circ }C)$, electricity and free radical. The process is known as initiation of free radical reaction.

$A:B\underrightarrow{\left(i\right)Peroxide}{A}^0+B^0$

(ii) hv
(iii) $\Delta$
(iv) Electricity or
(v) Free radical

$C{H}_3-H\underrightarrow{hv}\stackrel{\stackrel{.}{C{H}_3}}{\downarrow }+\stackrel{.}{H}$
methyl free radical

So, one of the necessary condition is:
It should be non - polar.
$\Rightarrow$ If there will electronegative difference, the compound will be polar.
In $Cl-Cl$ and $C{H}_3-H$, they both are non polar, hence Homolytic fission.