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.
$\underset{\text{Propene}}{C{H}_3-CH}==C{H}_2+HI\stackrel{\text{ Peroxide }}{\to }\underset{\text{1-iodopropane}}{C{H}_3-C{H}_2-C{H}_{2}I}$
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 $A$.