question_answer

What is the function of anhydrous \[ZnC{{l}_{2}}\] in the Lucas test of alcohols?

Answer:

                \[\underset{\begin{smallmatrix}                 \\                 \text{Alcohol} \end{smallmatrix}}{\mathop{-\underset{|}{\overset{|}{\mathop{C}}}\,}}\,-OH+HCl(g)\,\xrightarrow{ZnC{{l}_{2}}\,(anhyd.)}\,\underset{\begin{smallmatrix}                 \\                 \text{Alkyl}\,\,\text{chloride} \end{smallmatrix}}{\mathop{-\underset{|}{\overset{|}{\mathop{C}}}\,-Cl\,}}\,+{{H}_{2}}O\] Anhydrous \[ZnC{{l}_{2}}\] is a dehydrating agent and absorbs molecules of \[{{H}_{2}}O\] formed in the reaction. This enables the reaction to proceed in the forward direction.