Question

The correct order of rate of solvolysis for the following compounds is 

• A. III>II>I
• B. II>I>III
• C. III>I>II
• D. II>III>I

Hint:

Carbocation stability directly controls solvolysis rates. Benzylic>allylic>vinyl.

Answer 1

The Correct Option is D

Step 1: Understanding solvolysis.
Solvolysis of alkyl halides proceeds via formation of a carbocation intermediate. The more stable the carbocation, the faster the solvolysis rate. Aromatic and benzylic systems show enhanced carbocation stability due to resonance.
Step 2: Comparing structures.
Structure III forms the most stable carbocation because the benzylic position allows extensive resonance stabilization. Structure II forms an allylic carbocation, which is moderately stabilized. Structure I forms the least stable carbocation because the vinyl halide does not form a stable carbocation and no resonance stabilization is possible.
Step 3: Conclusion.
Thus the rate of solvolysis follows: III>II>I.