Benzoic acid in treament with `HNO_3` in the presence of `H_2 SO_4 ` gives

Options

A. m-nitrobenzoic acid
B. nitrobenzene
C. o- nitrobenzoic acid
D. Benzene sulphonic acid

Explanation

To determine the product of the reaction between benzoic acid and a mixture of nitric acid (HNO₃) and sulfuric acid (H₂SO₄), we can follow these steps:

### Step 1: Understand the Reaction Conditions
Benzoic acid (C₆H₅COOH) is treated with nitric acid in the presence of sulfuric acid. Sulfuric acid acts as a dehydrating agent and helps generate the nitronium ion (NO₂⁺) from nitric acid, which is a strong electrophile.

**Hint:** Remember that sulfuric acid enhances the electrophilic character of nitric acid by generating the nitronium ion.

### Step 2: Formation of the Electrophile
In the presence of sulfuric acid, nitric acid generates the nitronium ion (NO₂⁺) through the following reaction:
\[ \text{HNO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{NO}_2^+ + \text{HSO}_4^- + \text{H}_2\text{O} \]

**Hint:** Identify the electrophile that will attack the aromatic ring of benzoic acid.

### Step 3: Electrophilic Aromatic Substitution
Benzoic acid has a carboxylic acid group (-COOH) which is an electron-withdrawing group. This affects the positions on the benzene ring where the electrophile can attack. The electron-withdrawing nature of the -COOH group decreases electron density at the ortho and para positions, making the meta position more favorable for electrophilic attack.

**Hint:** Consider the directing effects of substituents on the benzene ring when determining where the electrophile will attack.

### Step 4: Identify the Product
The nitronium ion (NO₂⁺) will preferentially attack the meta position of benzoic acid due to the electron-withdrawing effect of the -COOH group. The product formed from this reaction is meta-nitrobenzoic acid (C₆H₄(NO₂)COOH).

**Hint:** Visualize the structure of benzoic acid and mark the positions where the electrophile can attack.

### Final Answer
The product of the reaction between benzoic acid and a mixture of nitric acid and sulfuric acid is **meta-nitrobenzoic acid**.

### Summary of Steps:
1. Understand the reaction conditions and the role of sulfuric acid.
2. Recognize the formation of the nitronium ion as the electrophile.
3. Analyze the directing effects of the -COOH group on the benzene ring.
4. Conclude that the product is meta-nitrobenzoic acid.