An aromatic, oxygen-containing compound 'X' gives a characteristic violet colour with neutral FeCl ₃ solution. When 'X' is heated with zinc dust, it forms a hydrocarbon 'Y'. Compound 'Y' on treatment with oleum gives 'Z'. Compound 'Z' on fusion with NaOH at high temperature followed by acidification regenerates 'X'. Identify the compounds 'Y' and 'Z' respectively.

Step-by-step solution

The characteristic violet colour with neutral FeCl ₃ solution indicates that compound 'X' is a phenol. Heating phenol (X) with zinc dust causes its reduction to benzene (compound 'Y'). Benzene undergoes sulfonation when treated with oleum (fuming sulfuric acid) to form benzenesulfonic acid (compound 'Z'). Fusion of benzenesulfonic acid with NaOH followed by acidification replaces the - SO ₃ H group with an - OH group, regenerating phenol (X). Thus, Y is benzene and Z is benzenesulfonic acid. Answer: Benzene and ben