Question

What is picric acid? How it is prepared from phenol?

Answer 1

Part 1: Picric acid

• Picric acid is the common name for $2,4,6-$ trinitrophenol.
• When phenol $\left({\mathrm{C}}_6{\mathrm{H}}_5\mathrm{OH}\right)$ is exposed to excessive nitration, picric acid is formed.

Part 2: Formation of picric acid from phenol

• Phenol reacts with concentrated sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ to form Phenoldisulfonic acid.
• Phenoldisulfonic acid reacts with concentrated nitric acid to give $2,4,6-$ trinitrophenol.
• The chemical reaction is as follows,