NEETChemistryAlcohols Phenols and Ethers
Match List-I with List-II regarding their reaction with Lucas reagent (conc. HCl + anhydrous ZnC l₂ ) at room temperature. List-I (Compound) List-II (Observation) (A) 2-Methylbutan-2-ol (I) Turbidity appears immediately (B) Pentan-3-ol (II) Turbidity appears after about 5 minutes (C) Butan-1-ol (III) Turbidity does not appear at room temperature (D) Phenol (IV) Does not react to form aryl halide Choose the correct an
Options
- A(A)-(II), (B)-(I), (C)-(III), (D)-(IV)
- B(A)-(I), (B)-(III), (C)-(II), (D)-(IV)
- C(A)-(I), (B)-(II), (C)-(III), (D)-(IV)
- D(A)-(IV), (B)-(II), (C)-(III), (D)-(I)
Correct answer
C. (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
Step-by-step solution
The Lucas test is used to distinguish between primary, secondary, and tertiary alcohols based on their reactivity with conc. HCl and anhydrous ZnC l₂ . 2-Methylbutan-2-ol is a tertiary (3 ^ ) alcohol. It reacts instantaneously via a stable tertiary carbocation to form an alkyl halide, giving immediate turbidity. Thus, (A) matches (I). Pentan-3-ol is a secondary (2 ^ ) alcohol. It reacts more slowly, producing turbidity after about 5 minutes. Thus, (B) matches (II). Butan-1-ol is a primary (1 ^ ) alcohol. It does no