Question

Which of the following alcohols reacts most readily with Lucas reagent?

• A. $C{H}_{3}C{H}_{2}C{H}_{2}OH$
• B. $(C{H}_3{)}_{2}CHOH$
• C. $(C{H}_3{)}_{3}COH$
• D. $C{H}_{3}C{H}_{2}OH$

Answer 1

Answer: (C)

$(C{H}_3{)}_{3}COH$

$(C{H}_3{)}_{3}COH$, a tertiary alcohol, reacts most readily with Lucas reagent.
Lucas reagent is a mixture of conc HCl and anhydrous zinc chloride. The reactivity of alcohols towards Lucas reagent follows the order: tertiary > secondary > primary.
When a tertiary alcohol, reacts with Lucas reagent, an oily layer (turbidity) is formed at once in cold.
When a secondary alcohol, reacts with Lucas reagent, a precipitate is formed after 5 to 10 minutes.
When a primary alcohol, is treated with Lucas reagent, no reaction is observed in cold conditions.