Identify the substrate 'S' in the following reaction.

Step-by-step solution

The given reaction is a nucleophilic aromatic substitution where a leaving group on the benzene ring is replaced by an - OH group from water to form 2,4,6-trinitrophenol (picric acid). Aryl halides are generally unreactive towards nucleophilic substitution. However, the presence of strong electron-withdrawing groups (like - NO ₂ ) at the ortho and para positions with respect to the halogen atom greatly increases their reactivity. In 2,4,6-trinitrochlorobenzene, there are three - NO ₂ groups at the ortho and para po