Concept:Phenol is a highly activated ring. Nitration conditions dictate the extent of substitution. While dilute \(\text{HNO}_3\) gives mono-nitration and concentrated gives tri-nitration (picric acid), intermediate conditions/mixed acids at specific temperatures can yield di-nitration products.
Formula:$$ \text{Phenol} + \text{HNO}_3/\text{H}_2\text{SO}_4 \longrightarrow \text{2,4-Dinitrophenol} $$
Solution:- To attach nitro groups to the phenol ring, a nitrating mixture containing \(\text{HNO}_3\) is required.
- Therefore, the reaction of phenol with a nitrating mixture \((\text{HNO}_3+\text{H}_2\text{SO}_4)\) leads to nitration at the ortho and para positions.
Why other options are incorrect:Option A yields nitrobenzene or dinitrobenzene, not a phenol derivative. Option B yields phenol (Dow process variant). Option D yields pure phenol without nitro groups.
Quality & Fidelity Assurance:
Every question on BeambePrep is rigorously curated against the official PMDC syllabus with zero filler, zero out-of-syllabus content, and zero typos. When an authentic past paper originally contained a historical mistake or ambiguity from the examining board (such as UHS or NUMS), BeambePrep faithfully reflects the original paper while detailing the nuance and scientific consensus in the autopsy above.