Give industrial preparation of benzoic acid from toluene.

Explanation

### Step-by-Step Solution for the Industrial Preparation of Benzoic Acid from Toluene

**Step 1: Chlorination of Toluene**
- Toluene (C7H8) undergoes chlorination in the presence of chlorine (Cl2) and ultraviolet light (hv).
- This reaction replaces three hydrogen atoms in toluene with chlorine atoms, resulting in the formation of trichlorotoluene (C7H5Cl3).

**Chemical Reaction:**
\[ \text{C}_7\text{H}_8 + 3 \text{Cl}_2 \xrightarrow{hv} \text{C}_7\text{H}_5\text{Cl}_3 + 3 \text{HCl} \]
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