Question

The rate for \( S_N1 \) reaction will be faster for which of the following bromides?

• A.

  

• B.

  

• C.

  

• D.

  

Hint:

For \( S_N1 \) reactions, the more stable the carbocation intermediate, the faster the reaction proceeds.

Answer 1

The Correct Option is A

\( S_N1 \) reaction proceeds via formation of a carbocation intermediate, and its rate depends on the stability of this carbocation.
Among the options:
- Benzyl carbocation (PhCH$_2^+$) is highly stable due to resonance with the benzene ring.
- Other options form either vinyl, secondary, or less stabilized carbocations.
Therefore, the reaction rate is fastest for benzyl bromide.