Question

Statement I: High concentration of strong nucleophilic reagent with secondary alkyl halides which do not have bulky substituents will follow \(S_N2\) mechanism.

Statement II: A secondary alkyl halide when treated with a large excess of ethanol follows \(S_N1\) mechanism.

In the light of the above statements, choose the most appropriate from the questions given below:

• A. Both statements are true
• B. Statement I is true, II is false
• C. Both statements are false
• D. Statement I is false, Statement II is true

Answer 1

The Correct Option is A

Statement I Analysis: S_N2 reactions involve a one-step process where the nucleophile attacks the substrate opposite the leaving group. Increased concentration of a strong nucleophile accelerates S_N2 reactions, particularly with unhindered secondary alkyl halides. Therefore, Statement I is accurate.

Statement II Analysis: S_N1 reactions proceed in two stages: carbocation formation and subsequent nucleophilic attack. Secondary alkyl halides can undergo S_N1 reactions in polar protic solvents such as ethanol. An excess of ethanol acts as a nucleophile and stabilizes the carbocation, promoting the S_N1 pathway. Consequently, Statement II is also accurate.

Conclusion: Both statements are correct. Statement I and Statement II are both true.