Which is`//`are ampoteric oxide ?

Options

A. `ZnO`
B. `BeO`
C. `SnO`
D. All of these

Answer

To determine which oxides are amphoteric, we need to understand the definition of amphoteric oxides. Amphoteric oxides are those that can react with both acids and bases. Let's analyze the given options step by step.

### Step-by-Step Solution:

1. **Identify the Oxides**: The oxides we need to analyze are:
- Zinc oxide (ZnO)
- Beryllium oxide (BeO)
- Stannous oxide (SnO)

2. **Analyze Zinc Oxide (ZnO)**:
- **Reaction with Acid**: When ZnO reacts with hydrochloric acid (HCl), it forms zinc chloride (ZnCl2) and water (H2O).
\[ \text{ZnO} + 2 \text{HCl} \rightarrow \text{ZnCl}_2 + \text{H}_2\text{O} \]
- **Reaction with Base**: When ZnO reacts with sodium hydroxide (NaOH), it forms sodium zincate (Na2ZnO2) and water.
\[ \text{ZnO} + 2 \text{NaOH} \rightarrow \text{Na}_2\text{ZnO}_2 + \text{H}_2\text{O} \]
- **Conclusion**: ZnO is an amphoteric oxide.

3. **Analyze Beryllium Oxide (BeO)**:
- **Reaction with Acid**: When BeO reacts with hydrochloric acid (HCl), it forms beryllium chloride (BeCl2) and water.
\[ \text{BeO} + 2 \text{HCl} \rightarrow \text{BeCl}_2 + \text{H}_2\text{O} \]
- **Reaction with Base**: When BeO reacts with sodium hydroxide (NaOH), it forms sodium beryllate (Na2BeO2) and water.
\[ \text{BeO} + 2 \text{NaOH} \rightarrow \text{Na}_2\text{BeO}_2 + \text{H}_2\text{O} \]
- **Conclusion**: BeO is also an amphoteric oxide.

4. **Analyze Stannous Oxide (SnO)**:
- **Reaction with Acid**: When SnO reacts with hydrochloric acid (HCl), it forms stannous chloride (SnCl2) and water.
\[ \text{SnO} + 2 \text{HCl} \rightarrow \text{SnCl}_2 + \text{H}_2\text{O} \]
- **Reaction with Base**: When SnO reacts with sodium hydroxide (NaOH), it forms sodium stannate (Na2SnO2) and water.
\[ \text{SnO} + 2 \text{NaOH} \rightarrow \text{Na}_2\text{SnO}_2 + \text{H}_2\text{O} \]
- **Conclusion**: SnO is also an amphoteric oxide.

5. **Final Conclusion**: Since all three oxides (ZnO, BeO, and SnO) can react with both acids and bases, they are all amphoteric oxides. Therefore, the correct answer is:
- **All of these are amphoteric oxides**.

### Summary:
The amphoteric oxides among the given options are:
- Zinc oxide (ZnO)
- Beryllium oxide (BeO)
- Stannous oxide (SnO)