Question

After Lucas test at room temperature, if mixture remains clear than which alcohol is confirmed?

• A. Isopropyl alcohol
• B. n-butyl alcohol
• C. Tertiary butyl alcohol
• D. None of the above

Answer 1

The correct option is B n-butyl alcohol

Lucas test is used to differentiate and categorize primary, secondary and tertiary alcohols using a solution of anhydrous zinc chloride in concentrated hydrochloric acid. This solution is commonly referred to as the Lucas reagent.
Primary, Secondary, and Tertiary alcohols react with the Lucas reagent to form the chloroalkane at different rates.

• The solution remains colorless unless it is subjected to heat in case of primary alcohol (n-butyl alcohol). The solution forms no turbidity.
• The solution turns turbid and forms an oily layer in 5 to 10 minutes in case of secondary alcohol ( Isopropyl alcohol).
• The solution turns turbid immediatly in case of tertiary alcohol (Tertiary butyl alcohol ).