This solution is used to classify alcohols of low molecular weight. The reaction is a substitution in which the chloride replaces a hydroxyl group. The best results for this test are observed in tertiary alcohols, as they form the respective alkyl halides fastest due to higher stability of the intermediate tertiary carbocation.

The Lucas test in alcohols is a test to differentiate between Primary , secondary , and Tertiary Alcohols. It is based on the difference in reactivity of the three classes of alcohols with hydrogen halides via an SN1 reaction.

Since, the Lucas reagent is Anhydrous $ZnCl _2$ and Conc. $HCl$.