Lucas' reagent is a solution of zinc chloride in concentrated hydrochloric acid, used to classify alcohols of low molecular weight. The reaction is a substitution in which the chlorine replaces the hydroxy group. Even though this reaction is normally very unfavorable, the zinc ion complexes with the hydroxy group (by accepting a lone electron pair from O of -OH), making it a better leaving group. The remaining carbonium ion then combines with the chloride ion to form an alkyl halide. Lucas Test is a chemical procedure that uses a mixture of strong hydrochloric acid and anhydrous zinc chloride to classify primary, secondary, and tertiary alcohols. Lucas Test is also called Lucas Reagent. Howard Lucas developed the Lucas Test in 1930. Lucas Reagent is a mixture of anhydrous zinc chloride and strong hydrochloric acid. When the reagent's clear and colorless characteristics change to turbid, foggy, and hazy ones, indicating the development of a chloroalkane, Lucas Test for ... Learn the Lucas Test in Chemistry—how it distinguishes primary, secondary, and tertiary alcohols using Lucas reagent. Includes procedure, reactions, and results. Learn the definition, procedure, observations, mechanism, applications and practice problems of Lucas test, a test to identify primary, secondary and tertiary alcohols using Lucas reagent. Lucas reagent is a solution of anhydrous zinc chloride and hydrochloric acid that reacts with alcohols to form chloroalkanes.
