Question

In the reaction R–OH + HCl $\xrightarrow{\text{ZnCl}_2}$ RCl + H$_2$O, what is the correct order of reactivity of alcohols?

• A. 1$^\circ$ $<$ 2$^\circ$ $<$ 3$^\circ$
• B. 2$^\circ$ $<$ 1$^\circ$ $<$ 3$^\circ$
• C. 3$^\circ$ $>$ 1$^\circ$ $<$ 2$^\circ$
• D. 1$^\circ$ $>$ 2$^\circ$ $>$ 3$^\circ$

Hint:

More substituted alcohols form more stable carbocations, increasing reactivity.

Answer 1

The Correct Option is A

Tertiary alcohols react most rapidly with Lucas reagent (HCl + ZnCl$_2$) because they form stable carbocations, resulting in the reactivity order 1$^\circ$<2$^\circ$<3$^\circ$.