In the following reaction sequence, X and Z respectively are : 3 CH ₃ OH + PCl ₃ 3 CH ₃ Cl + X CH ₃ Cl KCN (alc.) Y H ₃ O ^+, Z

Step-by-step solution

The reaction of an alcohol with phosphorus trichloride ( PCl ₃ ) yields an alkyl chloride and phosphorous acid ( H ₃ PO ₃ ). 3 CH ₃ OH + PCl ₃ 3 CH ₃ Cl + H ₃ PO ₃ Thus, X is H ₃ PO ₃ . Methyl chloride undergoes nucleophilic substitution with alcoholic KCN to form methyl cyanide (acetonitrile). CH ₃ Cl KCN (alc.) CH ₃ CN Thus, Y is CH ₃ CN . Complete acid hydrolysis of methyl cyanide yields acetic acid. CH ₃ CN H ₃ O ^+, CH ₃ COOH + NH ₄^+ Thus, Z is CH ₃ COOH . Answer: X = H ₃ PO ₃ ; Z = CH ₃ COOH