Question

Which of following alcohols gives white turbidity almost immediately with the Lucas reagent at room temperature?
(i) n-Butanol
(ii) tertiary-Butanol
(iii) Benzyl alcohol
(iv) Allylic alcohol

• A. (i), (ii) and (iii)
• B. (i), (iii) and (iv)
• C. (ii), (iii) and (iv)
• D. (i), (ii) and (iv)

Answer 1

Answer: (C)

Lucas reagent react with alcohols used to differentiate between primary, secondary and tertiary alcohols. Tertiary alcohols react immediately with Lucas reagent as evidenced by turbidity owing to the low solubility of the organic chloride in the aqueous mixture.
(i)$CH _{3}- CH _{2}-\underset{n-\text { butanol }}{ CH _{2}}- CH _{2}- OH , 1^{\circ}$
alcohol -not give reaction

$1^{\circ}$ alcohol benzylic cation -white turbidity
(iv) $CH _{3}= CH - CH _{2}- OH -1^{\circ}$ alcohol allylic cation-white turbidity,