The hydroxyl compound that gives a precipitate immediately when treated with concentrated hydrochloric acid and anhydrous zinc chloride is

Question

The hydroxyl compound that gives a precipitate immediately when treated with concentrated hydrochloric acid and anhydrous zinc chloride is (A) 3-methyl-2-butanol (B) 3-methyl-1-butanol (C) 1-butanol (D) 2-methyl-2-butanol

Tardigrade Admin · Accepted Answer

An equimolar mixture of cone. HCl and anhydrous ZnCl2 is called Lucas reagent. On treatement with Lucas reagent, tertiary alcohols gives precipitate immediately. This test is known as Lucas test. underset beginsmallmatrix 2-methyl-2-butanol (3° alcohol) endsmallmatrix mathopCH3- underset beginsmallmatrix | CH3 endsmallmatrix overset beginsmallmatrix OH | endsmallmatrix mathopC -CH2-CH3 xrightarrow[+anhy. ZnCl2]HCl underset beginsmallmatrix 2-chloro-2-methylbutane (Turbidity text appears text immediately) endsmallmatrix mathopCH3- underset beginsmallmatrix | CH3 endsmallmatrix overset beginsmallmatrix Cl | endsmallmatrix mathopC -CH2-CH3

Q. The hydroxyl compound that gives a precipitate immediately when treated with concentrated hydrochloric acid and anhydrous zinc chloride is

$3$ -methyl- $2$ -butanol

$3$ -methyl- $1$ -butanol

$1$ -butanol

$2$ -methyl- $2$ -butanol

$2, 3$ -dimethyl- $1$ -butanol

Q. The hydroxyl compound that gives a precipitate immediately when treated with concentrated hydrochloric acid and anhydrous zinc chloride is

3-methyl-2-butanol

3-methyl-1-butanol

1-butanol

2-methyl-2-butanol

2,3-dimethyl-1-butanol

$3$ -methyl- $2$ -butanol

$3$ -methyl- $1$ -butanol

$1$ -butanol

$2$ -methyl- $2$ -butanol

$2, 3$ -dimethyl- $1$ -butanol