Question

Assertion (A) Propene reacts with $HI$ in the presence of peroxide to give $1$-iodopropane.
Reason (R) $1^{\circ}$ free radical is less stable than $2^{\circ}$ free radical.

• A. Both $A$ and $R$ are correct; $R$ is the correct explanation of $A$
• B. Both $A$ and $R$ are correct; $R$ is not the correct explanation of $A$
• C. $A$ is correct; $R$ is incorrect
• D. $R$ is correct; $A$ is incorrect

Answer 1

Answer: (B)

When propene reacts with $HI$ in the presence of peroxide, it shows anti-Markovnikov's addition. Thus, 1-iodopropane is obtained as major product.
$\underset{\text{Propene}}{CH _{3}- CH}== CH _{2}+ HI \xrightarrow{\text { Peroxide }} \underset{\text{1-iodopropane}}{CH _{3}- CH _{2}- CH _{2} I}$
It is also true that, $2^{\circ}$ free radical is more stable than $1^{\circ}$ free radical but it is not the reason of the given assertion.
Thus, both $A$ and $R$ are correct but $R$ is not the correct explanation for $A$.