question_answer 90)

  Why is the reactivity of all the three classes of alcohols with cone. HCl and  (Lucas reagent) different ?

Answer:

                  The reaction of alcohols with cone. HCl and  (Lucas reagent) occurs through intermediate formation of carbocations. Obviously, more stable the carbocation, more reactive is the alcohol. Since the stability of carbocations follows the order : 3° > 2° > 1°, therefore, reactivity of alcohols towards Lucas reagent follows the same order, i.e., 3° > 2° > 1°.