Benzene on treating with a mixture of conc. `HNO_(3) and H_(2)SO_(4)` at `100^(@)C` gives

Options

A. Nitrobenzene
B. m - dinitrobenzene
C. o - dinitrobenzene
D. p - dinitrobenzene

Explanation

To solve the question of what benzene produces when treated with a mixture of concentrated nitric acid (HNO₃) and concentrated sulfuric acid (H₂SO₄) at 100°C, we can follow these steps:

### Step 1: Understand the Reaction Conditions
Benzene is treated with a mixture of concentrated nitric acid and concentrated sulfuric acid. This mixture is known as nitrating mixture and is used for the nitration of aromatic compounds.

**Hint:** Remember that nitration involves the introduction of a nitro group (-NO₂) into the aromatic ring.

### Step 2: Identify the Electrophile
In the nitrating mixture, concentrated sulfuric acid protonates the nitric acid, generating the nitronium ion (NO₂⁺), which is the active electrophile in this reaction.

**Hint:** Electrophiles are species that seek electrons and can react with nucleophiles, such as the benzene ring.

### Step 3: Electrophilic Aromatic Substitution
Benzene, being an electron-rich aromatic compound, will undergo electrophilic aromatic substitution. The nitronium ion (NO₂⁺) will attack the benzene ring, leading to the formation of nitrobenzene.

**Hint:** The aromatic nature of benzene allows it to stabilize the positive charge that develops during the reaction.

### Step 4: Consider the Temperature Effect
At 100°C, the reaction is more vigorous, and there is a possibility of multiple nitration events. However, the primary product formed will be nitrobenzene (C₆H₅NO₂). If the reaction continues, further nitration can occur, leading to the formation of dinitrobenzene (C₆H₄(NO₂)₂).

**Hint:** Higher temperatures can lead to multiple substitutions on the benzene ring.

### Step 5: Determine the Final Product
Since the question specifies treatment at 100°C, we can conclude that the major product will be dinitrobenzene, specifically the meta isomer due to the directing effects of the nitro group.

**Final Answer:** The product of benzene treated with a mixture of concentrated HNO₃ and H₂SO₄ at 100°C is **meta-dinitrobenzene**.

### Summary of Steps:
1. Recognize the reaction conditions (nitrating mixture).
2. Identify the electrophile (nitronium ion).
3. Understand the mechanism (electrophilic aromatic substitution).
4. Consider the effect of temperature on the reaction.
5. Conclude the final product (meta-dinitrobenzene).