Which of the following oxides is amphoteric in nature?

Options

A. `Al_2 O_3`
B. `B_2 O_3`
C. `Tl_2 O_3`
D. `In_2 O_3`

Answer

To determine which of the given oxides is amphoteric in nature, we need to analyze the behavior of each oxide in reactions with acids and bases.

### Step-by-Step Solution:

1. **Understanding Amphoteric Oxides**:
Amphoteric oxides are those that can react with both acids and bases, exhibiting both acidic and basic properties.

2. **Evaluating Al₂O₃ (Aluminum Oxide)**:
- **Reaction with Acid**:
\[ \text{Al}_2\text{O}_3 + 6 \text{HCl} \rightarrow 2 \text{AlCl}_3 + 3 \text{H}_2\text{O} \]
Here, Al₂O₃ behaves as a base.
- **Reaction with Base**:
\[ \text{Al}_2\text{O}_3 + 2 \text{NaOH} + 3 \text{H}_2\text{O} \rightarrow 2 \text{NaAlO}_2 \]
In this case, Al₂O₃ acts as an acid.
- **Conclusion**: Al₂O₃ is amphoteric.

3. **Evaluating B₂O₃ (Boron Oxide)**:
- **Reaction with Base**:
\[ \text{B}_2\text{O}_3 + 2 \text{NaOH} \rightarrow 2 \text{NaBO}_2 + \text{H}_2\text{O} \]
Here, B₂O₃ acts as an acid.
- **Conclusion**: B₂O₃ is not amphoteric; it is acidic.

4. **Evaluating Ti₂O₃ (Titanium Oxide)**:
- **Reaction with Acid**:
\[ \text{Ti}_2\text{O}_3 + 3 \text{H}_2\text{SO}_4 \rightarrow \text{Ti}_2(\text{SO}_4)_3 + 3 \text{H}_2\text{O} \]
Ti₂O₃ acts as a base.
- **Conclusion**: Ti₂O₃ is not amphoteric; it is basic.

5. **Evaluating In₂O₃ (Indium Oxide)**:
- **Reaction with Acid**:
\[ \text{In}_2\text{O}_3 + 6 \text{HCl} \rightarrow 2 \text{InCl}_3 + 3 \text{H}_2\text{O} \]
In₂O₃ acts as a base.
- **Conclusion**: In₂O₃ is not amphoteric; it is basic.

6. **Final Conclusion**:
Among the given oxides, Al₂O₃ is the only one that exhibits both acidic and basic characteristics, thus it is the amphoteric oxide.

### Answer:
The amphoteric oxide is **Al₂O₃**.