Why is the reactivity of all the three classes of alcohols with conc. HCl and ZnCl₂ (Lucas reagent) different? 

<p><span data-teams="true">This is a short answer type question as classified in NCERT Exemplar</span></p><p>The reaction of alcohol with the conc. HCl and ZnCl₂ (Lucas reagent) leads to the formation of a carbocation through SN¹&nbsp; mechanism. The more stable the carbocation, the faster the reaction will be.</p><p>Tertiary carbocation is the most stable due to hyperconjugation and inductive effect then is the secondary alcohol and the primary alcohol is the least stable.</p><p><strong>Stability of carbocation:</strong></p><p>Tertiary carbocation &gt; Secondary carbocation&nbsp; &gt; Primary carbocation&nbsp;</p><p><strong>According to stability of carbocation, the reactivity order of the alcohol is:</strong></p><p>Tertiary alcohol &gt; Secondary alcohol&nbsp; &gt; Primary alcohol&nbsp;</p><p>Tertiary alcohol reacts immediately with Lucas reagent and shows turbidity, secondary alcohol does not show turbidity with Lucas reagent at room temperature but on heating turbidity appears and primary alcohol do not react with lucas reagent even on heating.</p>

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