Oxide of metal cation which is not amphoteric ?

Options

A. `Al^(3+)`
B. `Cr^(3+)`
C. `Fe^(3+)`
D. `Zn^(2+)`

Explanation

To determine which oxide of a metal cation is not amphoteric, we need to understand the definition of amphoteric oxides. Amphoteric oxides are those that can react with both acids and bases.

### Step-by-Step Solution:

1. **Understand Amphoteric Oxides**:
- Amphoteric oxides can react with both acids and bases.
- Examples include oxides of metals like aluminum (Al), zinc (Zn), and chromium (Cr).

2. **Identify the Given Cations**:
- The question provides us with four metal cations: Aluminum (Al³⁺), Chromium (Cr³⁺), Zinc (Zn²⁺), and Iron (Fe³⁺).

3. **Analyze Each Cation**:
- **Aluminum Oxide (Al₂O₃)**: This oxide is amphoteric as it reacts with both acids (like HCl) and bases (like NaOH).
- **Chromium Oxide (Cr₂O₃)**: This oxide is also amphoteric, reacting with both acids and bases.
- **Zinc Oxide (ZnO)**: Zinc oxide is amphoteric as well, reacting with acids and bases.
- **Iron Oxide (Fe₂O₃)**: Ferric oxide (Fe₂O₃) is primarily acidic and does not react with bases, making it not amphoteric.

4. **Conclusion**:
- Among the options provided, the oxide of the metal cation that is not amphoteric is the oxide of Iron (Fe³⁺).

### Final Answer:
The oxide of metal cation which is not amphoteric is Iron (Fe³⁺).