Which of the following statements is correct:

Options

A. Bromination of toluene occurs faster than that of benzene
B. Nitration of toluene is faster than that of ethylbenzene
C. The bromonium ion is a good nucleophile
D. Effective nitrating agent is nitrate ion

Answer

To determine which of the statements provided is correct regarding the bromination and nitration of aromatic compounds, we can analyze each statement step by step.

### Step 1: Analyze the Bromination of Toluene vs. Benzene
- **Statement**: Bromination of Toluene occurs faster than that of Benzene.
- **Explanation**:
- Bromination is an electrophilic aromatic substitution reaction.
- Toluene has a methyl group (-CH₃) which is an electron-donating group due to hyperconjugation. This increases the electron density on the aromatic ring of toluene.
- Benzene, on the other hand, does not have any substituents that increase its electron density.
- Since toluene is more electron-rich, it is more reactive towards electrophiles like the bromonium ion, making bromination occur faster in toluene than in benzene.

### Step 2: Analyze the Nitration of Toluene vs. Ethylbenzene
- **Statement**: Nitration of Toluene is faster than that of Ethylbenzene.
- **Explanation**:
- Nitration involves the nitronium ion (NO₂⁺), which is also an electrophile.
- Toluene has three alpha hydrogens, while ethylbenzene has two. The presence of more alpha hydrogens in toluene allows for greater hyperconjugation, further increasing the electron density on its aromatic ring.
- As a result, toluene is more electron-rich than ethylbenzene, making it more reactive towards nitration. Therefore, nitration of toluene occurs faster than that of ethylbenzene.

### Step 3: Evaluate the Nature of Brominium Ion
- **Statement**: Brominium ion is a good nucleophile.
- **Explanation**:
- The brominium ion is formed from bromine (Br₂) in the presence of an alkene and is an electrophile, not a nucleophile.
- It is positively charged and seeks electrons, which is characteristic of electrophiles. Thus, this statement is incorrect.

### Step 4: Identify the Effective Nitrating Agent
- **Statement**: The effective nitrating agent is NO₂⁺ (Nitronium ion), while nitrate (NO₃⁻) is not electrophilic.
- **Explanation**:
- The nitronium ion (NO₂⁺) is indeed the active electrophile in nitration reactions.
- Nitrate (NO₃⁻) is a negatively charged ion and acts as a nucleophile, not an electrophile. Therefore, this statement is correct.

### Conclusion:
- The correct statements are:
1. Bromination of Toluene occurs faster than that of Benzene.
2. Nitration of Toluene is faster than that of Ethylbenzene.
3. The effective nitrating agent is NO₂⁺ (Nitronium ion), while nitrate (NO₃⁻) is not electrophilic.

### Final Answer:
The correct statements are:
- Bromination of Toluene occurs faster than that of Benzene.
- Nitration of Toluene is faster than that of Ethylbenzene.
- The effective nitrating agent is NO₂⁺ (Nitronium ion).