Question

What happens when phenol is treated with conc ${\mathrm{HNO}}_3$ ?

Answer 1

1. Conc ${\mathrm{HNO}}_3$ is used for the nitration of the compound.
2. It is a electrophilic substitution reaction.
3. The $\mathrm{OH}$ group activates the ortho and para positions in the ring.
4. Due to resonance effects these positions become electron rich.
5. This is a complex reaction because conc ${\mathrm{HNO}}_3$ is an oxidising agent and hence oxidises Phenol to give tarry products.
6. With conc ${\mathrm{HNO}}_3$, phenol is converted to 2,4,6-trinitrophenol also known as picric acid in presence of Sulphuric acid which act as a catalyst.
7. The yield of the reaction is poor.
8.