Which one of the following statements on the nitration of aromatic compounds is false?

Options

A. the rate of nitration of benzene is almost the same as that of hexadeuterbenzene
B. The rate of nitration to toluene is greater than that of benzene .
C. The rate of nitration of benzene if greater than that of hexadeuterobenzne .
D. Nitration is an electrophilic substitution reaction .

Answer

To determine which statement about the nitration of aromatic compounds is false, we will analyze the provided options step by step.

### Step 1: Understanding Nitration
Nitration is the process of introducing one or more nitro groups (-NO2) into an aromatic compound. This typically involves the reaction of the aromatic compound with a nitrating agent, commonly a mixture of nitric acid (HNO3) and sulfuric acid (H2SO4).

**Hint:** Remember that nitration is an electrophilic substitution reaction where the nitro group replaces a hydrogen atom on the aromatic ring.

### Step 2: Identifying Nitrating Agents
The main nitrating agents include fuming nitric acid, concentrated nitric acid, and mixtures of nitric acid with sulfuric acid. The electrophile generated during this reaction is the nitronium ion (NO2+).

**Hint:** Focus on the role of sulfuric acid in generating the nitronium ion, which is crucial for the nitration process.

### Step 3: Analyzing the Statements
Now, we will evaluate the statements provided in the question:

1. **Rate of nitration of benzene is almost the same as that of hexadeuterobenzene.**
- This statement is **true** because the presence of deuterium (D) instead of hydrogen (H) does not significantly affect the rate of nitration. The bond-breaking step is not influenced by the mass of the hydrogen atom.

2. **Rate of nitration of toluene is greater than that of benzene.**
- This statement is **true** because the methyl group in toluene is an electron-donating group, which increases the electron density of the aromatic ring, making it more reactive towards electrophilic substitution.

3. **Rate of nitration of benzene is greater than that of hexadeuterobenzene.**
- This statement is **false** because, as established earlier, the rate of nitration does not depend on whether the hydrogen is replaced by deuterium. The rates of nitration for both compounds are essentially the same.

4. **Nitration is an electrophilic substitution reaction.**
- This statement is **true** as nitration involves the substitution of a hydrogen atom with a nitro group via an electrophilic mechanism.

### Conclusion
The false statement among the options provided is:
- **The rate of nitration of benzene is greater than that of hexadeuterobenzene.**

**Final Answer:** The false statement is that the rate of nitration of benzene is greater than that of hexadeuterobenzene.