Which given pair metals can be dissolves in `NaOH` solution ?

Options

A. Al , Cu
B. Zn , Al
C. Zn , Cu
D. Zn , Hg

Answer

To determine which pair of metals can be dissolved in a sodium hydroxide (NaOH) solution, we need to identify the metals that are amphoteric in nature. Amphoteric metals can react with both acids and bases.

### Step-by-Step Solution:

1. **Understanding Amphoteric Metals**:
- Amphoteric metals are those that can react with both acids and bases. They can dissolve in NaOH (a base) as well as in acids.

2. **Identifying Metals**:
- The metals mentioned in the question are Aluminum (Al), Copper (Cu), and Zinc (Zn).
- Among these, we need to identify which ones are amphoteric.

3. **Checking Each Metal**:
- **Aluminum (Al)**:
- Aluminum is amphoteric. It can react with NaOH to form sodium aluminate.
- Reaction:
\[ 2NaOH + 2H_2O + 2Al \rightarrow 2NaAlO_2 + 3H_2 \]
- **Copper (Cu)**:
- Copper is not amphoteric. It does not react with NaOH.
- **Zinc (Zn)**:
- Zinc is also amphoteric. It can react with NaOH to form sodium zincate.
- Reaction:
\[ Zn + 2NaOH \rightarrow Na_2ZnO_2 + H_2 \]

4. **Conclusion**:
- The metals that can dissolve in NaOH solution are Aluminum and Zinc.
- Therefore, the correct answer to the question is the pair: **Zinc and Aluminum**.

### Final Answer:
The pair of metals that can be dissolved in NaOH solution is **Zinc and Aluminum**.

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