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

Options

A. 3-methyl-2-butanol
B. 3-methyl-1-butanol
C. 1-butanol
D. 2-methyl-2-butanol

Answer

D

Explanation

An equimolar mixture of conc. HCl and anhydrous `ZnCl_(2)` is called Lucas reagent. On treatement with Lucas reagent, tertiary alcohols gives precipitate immediately. This test is known as Lucas test.
`underset((3^(@) "alcohol"))underset("2-methyl-2-butanol")(CH_(3) - underset(CH_(3))underset(|)overset(OH)overset(|)(C) - CH_(2) - CH_(3)) underset("+ anhy. ZnCl"_(2))overset(HCl)(rarr) underset(("Turbidity appears immediately"))underset("2-chloro-2-methylutane")(CH_(3) - underset(CH_(3))underset(|)overset(Cl)overset(|)(C) - CH_(2) - CH_(3))`