Which of the following statements is not correct ?

Options

A. Aliphatic amines are stronger bases than ammonia.
B. Aromatic amines are stronger bases than ammonia.
C. The alkyl group in alkyl ammonium ion more stabilizes the ion
relative to amine.
D. None of these

Answer

To solve the question "Which of the following statements is not correct?" regarding amines, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Evaluate Statement 1**: "Aliphatic amines are stronger bases than ammonia."
- **Analysis**: Aliphatic amines (e.g., RNH2) have alkyl groups that are electron-donating. This increases the electron density on the nitrogen atom, making it more capable of donating its lone pair of electrons compared to ammonia (NH3). Therefore, this statement is **correct**.

2. **Evaluate Statement 2**: "Aromatic amines are stronger bases than ammonia."
- **Analysis**: Aromatic amines (e.g., aniline) have a lone pair of electrons on nitrogen that gets delocalized into the aromatic ring due to resonance. This delocalization reduces the availability of the lone pair for protonation, making aromatic amines less basic than ammonia. Therefore, this statement is **incorrect**.

3. **Evaluate Statement 3**: "The alkyl group in alkyl ammonium ion stabilizes the ion relative to the amine."
- **Analysis**: Alkyl groups do stabilize the alkyl ammonium ion (RNH3+) through inductive effects and hydrogen bonding. This stabilization is due to the presence of alkyl groups that can donate electron density. Therefore, this statement is **correct**.

4. **Evaluate Statement 4**: "None of these."
- **Analysis**: Since we have identified that Statement 2 is incorrect, this statement is also **incorrect**.

### Conclusion:
The statement that is not correct is **Statement 2**: "Aromatic amines are stronger bases than ammonia."