Benzoic acid not form in :

Options

A.
B.
C.
D.

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:**
The question asks where benzoic acid is NOT formed. We need to analyze each option provided to determine if benzoic acid can be synthesized from the given compound.

2. **Analyzing Option 1: Toluene**
- Toluene (C6H5CH3) can be oxidized to benzoic acid (C6H5COOH) using KMnO4 and KOH under heating.
- Reaction:
\[ \text{C6H5CH3} + \text{KMnO4} \xrightarrow{\text{KOH, heat}} \text{C6H5COOK} \xrightarrow{\text{H}^+} \text{C6H5COOH} \]
- Conclusion: Benzoic acid is formed from toluene.

3. **Analyzing Option 2: Ethylene (CH2=CH2)**
- Ethylene can be oxidized to form carboxylic acids, but it does not lead to benzoic acid specifically.
- However, if we consider a substituted alkene, it can oxidize to yield carboxylic acids.
- Conclusion: This option does not specifically lead to benzoic acid, but it does not rule it out entirely.

4. **Analyzing Option 3: Benzonitrile (C6H5CN)**
- Benzonitrile can be hydrolyzed to benzoic acid in the presence of water and dilute HCl.
- Reaction:
\[ \text{C6H5CN} + \text{H2O} \xrightarrow{\text{HCl, heat}} \text{C6H5COOH} + \text{NH4}^+ + \text{Cl}^- \]
- Conclusion: Benzoic acid is formed from benzonitrile.

5. **Analyzing Option 4: Acetic Anhydride (O=C(O)C=O)**
- Acetic anhydride does not lead to the formation of benzoic acid. Instead, it can lead to the formation of phenol under acidic conditions.
- Reaction:
\[ \text{O=C(O)C=O} + \text{H3O}^+ \rightarrow \text{Phenol} \]
- Conclusion: Benzoic acid is NOT formed from acetic anhydride.

6. **Final Conclusion:**
- Based on the analysis, the compound from which benzoic acid is NOT formed is **Option 4: Acetic Anhydride**.

**Answer: Option 4 - Acetic Anhydride**

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