Assertion A : Hydrolysis of an alkyl chloride is a slow reaction but in the presence of NaI, the rate of the hydrolysis increases.
Reason R : is a good nucleophile as well as a good leaving group.
In the light of the above statements, choose the correct answer from the options given below
Reason R : is a good nucleophile as well as a good leaving group.
In the light of the above statements, choose the correct answer from the options given below
- A.A is true but R is false
- B.Both A and R are true but R is NOT the correct explanation of A
- C.A is false but R is true
- D.Both A and R are true and R is the correct explanation of A
Show answer and solution
Correct option: D
Solution
I⁻ is both a strong nucleophile and an excellent leaving group. In the presence of NaI, I⁻ first rapidly displaces Cl⁻ from the alkyl chloride (SN2) to form an alkyl iodide (since I⁻ is a far better nucleophile than Cl⁻ and I⁻ is a better leaving group than Cl⁻, this step is fast). The alkyl iodide then undergoes hydrolysis much faster than the original alkyl chloride because I⁻ is a much better leaving group than Cl⁻. Thus NaI acts as a catalyst, and R correctly explains why A is true.
[JEE Main 2023 · 24 Jan · Shift 1 · Paper-1(B.E./B. Tech.)]