Which of the following metals will react with NaOH and KOH to liberate hydrogen gas?

Options

A. Zn, Al, Fe and Mg
B. Al, Fe, Mg and Sn
C. Zn, Sn and Al
D. Fe, Mg and Al

Explanation

To determine which metals will react with sodium hydroxide (NaOH) and potassium hydroxide (KOH) to liberate hydrogen gas, we need to analyze the reactivity of various metals with strong bases.

### Step-by-Step Solution:

1. **Understanding the Reaction**:
- Metals can react with strong bases like NaOH and KOH to produce hydrogen gas (H₂). This typically occurs with amphoteric metals, which can react with both acids and bases.

2. **Identifying Amphoteric Metals**:
- Amphoteric metals are those that can react with both acids and bases. Common examples include aluminum (Al), zinc (Zn), and tin (Sn).

3. **Analyzing Each Metal**:
- **Aluminum (Al)**: Reacts with NaOH and KOH to produce hydrogen gas.
- **Zinc (Zn)**: Also reacts with NaOH and KOH to liberate hydrogen gas.
- **Tin (Sn)**: Reacts with NaOH and KOH to produce hydrogen gas as well.
- **Iron (Fe)**: Does not react with NaOH or KOH to liberate hydrogen gas.
- **Magnesium (Mg)**: While it can react with acids, it does not react with NaOH or KOH under normal conditions.
- **Lead (Pb)**: Generally does not react with NaOH or KOH to liberate hydrogen gas.

4. **Conclusion**:
- From the analysis, the metals that react with NaOH and KOH to liberate hydrogen gas are aluminum (Al), zinc (Zn), and tin (Sn). Therefore, the correct answer includes these metals.

### Final Answer:
The metals that will react with NaOH and KOH to liberate hydrogen gas are **Aluminum (Al), Zinc (Zn), and Tin (Sn)**.

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