Question

Lucas reagent is [MP PMT 1996; MP PET 1992, 95; CPMT 1986, 89; AIIMS 1980; Kurukshetra CEE 2002]
A) Concentrated HCl+\text{anhydrous }ZnC{{l}_{2}} B) Dilute HCl+\text{ hydrated }ZnC{{l}_{2}} C) Concentrated HN{{O}_{3}}+\text{ anhydrous }ZnC{{l}_{2}} D) Concentrated HCl+\text{ anhydrous }MgC{{l}_{2}}

Answer 1

Lucas reagent is Anhydrous $ZnCl_{2}$ + concentrated HCl.

It is used to distinguish between alcohols. Tertiary alcohols produce immediate turbidity (solution becomes cloudy) when reacted with Lucas reagent. Secondary alcohols produce turbidity after some time. However, primary alcohols do not produce turbidity at lab temperature and require heating to produce turbidity. Thus, Lucas reagent can be used to distinguish alcohols.

Hence, option (A) is the correct answer.