Nitrosobenzene can be prepared from aniline and which of the following

Options

A. Ethanol
B. Acetaldehyde
C. Acetone
D. Accetic anhydride

Answer

To solve the question "Nitrosobenzene can be prepared from aniline and which of the following?", we need to understand the process of preparing nitrosobenzene from aniline.

### Step-by-Step Solution:

1. **Identify Aniline**: Aniline (C6H5NH2) is an aromatic amine that contains an amino group (-NH2) attached to a benzene ring. This amino group is nucleophilic, meaning it can donate a pair of electrons.

2. **Understand the Reaction**: To prepare nitrosobenzene (C6H5NO), we need to convert the amino group of aniline into a nitroso group (-NO). This is typically done through a reaction with nitrous acid (HNO2).

3. **Reagents Required**: The common method to form nitrosobenzene from aniline involves treating aniline with nitrous acid, which can be generated in situ by mixing sodium nitrite (NaNO2) with a mineral acid like hydrochloric acid (HCl).

4. **Reaction Mechanism**:
- When aniline is treated with nitrous acid, it forms a diazonium salt (C6H5N2+), which is unstable at higher temperatures.
- The diazonium salt can then lose nitrogen gas (N2) to form nitrosobenzene.

5. **Final Product**: The final product of the reaction is nitrosobenzene (C6H5NO).

### Conclusion:
Thus, nitrosobenzene can be prepared from aniline and nitrous acid (or sodium nitrite and a mineral acid).

### Answer:
The correct option is **nitrous acid (HNO2)** or **sodium nitrite (NaNO2) with HCl**.

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