In the following reaction, two products X and Y are formed: \ce{C6H5OH ->[\text{conc. } HNO3][\text{conc. } H2SO4] X + Y} where X and Y are $o$-nitrophenol and $p$-nitrophenol. The suitable method that can be used for the separation of products X and Y is:

Solution & Explanation

\textbf{Answer:} (A) Fractional distillation \textbf{Solution:} Nitration of phenol gives a mixture of $o$-nitrophenol and $p$-nitrophenol. These differ appreciably in boiling point ($o$-nitrophenol b.p. $222\,^\circ$C, $p$-nitrophenol b.p. $238\,^\circ$C), because $o$-nitrophenol has intramolecular H-bonding (more volatile) while $p$-nitrophenol has intermolecular H-bonding (less volatile). A mixture of two liquids/low-melting solids whose boiling points differ can be separated by fractional distillation (under reduced pressure). Hence the correct method is fractional distillation.