Which of the following can react with both HCl and NaOH ?

Options

A. `Zn(OH)_(2)`
B. BeO
C. `Al_(2)O_(3)`
D. All of these

Answer

To determine which of the following can react with both HCl and NaOH, we need to identify substances that exhibit amphoteric behavior. Amphoteric substances can react with both acids and bases.

### Step-by-Step Solution:

1. **Understanding Amphoteric Substances**:
- Amphoteric substances are those that can react with both acids (like HCl) and bases (like NaOH).
- Common examples include metal oxides and hydroxides such as zinc oxide (ZnO), aluminum oxide (Al2O3), and beryllium oxide (BeO).

2. **Identifying the Candidates**:
- We need to check the given options (not provided here, but let's assume they include ZnO, Al2O3, BeO, etc.) to see which ones are amphoteric.

3. **Reactions with HCl**:
- **Zinc Oxide (ZnO)**:
- ZnO + 2HCl → ZnCl2 + H2O
- **Aluminum Oxide (Al2O3)**:
- Al2O3 + 6HCl → 2AlCl3 + 3H2O
- **Beryllium Oxide (BeO)**:
- BeO + 2HCl → BeCl2 + H2O

4. **Reactions with NaOH**:
- **Zinc Oxide (ZnO)**:
- ZnO + 2NaOH + 2H2O → Na2[Zn(OH)4] (sodium zincate)
- **Aluminum Oxide (Al2O3)**:
- Al2O3 + 2NaOH + 3H2O → 2NaAl(OH)4 (sodium aluminate)
- **Beryllium Oxide (BeO)**:
- BeO + 2NaOH + 2H2O → Na2[Be(OH)4] (sodium beryllate)

5. **Conclusion**:
- All the amphoteric substances mentioned (ZnO, Al2O3, BeO) can react with both HCl and NaOH. Therefore, the answer is that all amphoteric compounds can react with both.

### Final Answer:
The substances that can react with both HCl and NaOH are amphoteric compounds, such as ZnO, Al2O3, and BeO.