Question

Conc. HNO\(_3\) 

Hint:

Concentrated nitric acid causes electrophilic nitration of phenol, predominantly at the ortho and para positions, leading to trinitrophenol (picric acid).

Answer 1

When phenol reacts with concentrated nitric acid (HNO₃), it undergoes nitration at the ortho and para positions relative to the hydroxyl group. The major product is 2,4,6-Trinitrophenol (picric acid), which is highly reactive due to the electron-donating effect of the hydroxyl group, activating the ring for nitration.

\[ \text{C}_6\text{H}_5\text{OH} + 3\text{HNO}_3 \rightarrow \text{C}_6\text{H}_2(\text{NO}_2)_3\text{OH} + 3\text{H}_2\text{O} \]