The metal which produces hydrogen gas on reaction with dilute hydrochloric acid as well as sodium hydroxide solution is

Options

A. copper
B. aluminium
C. iron
D. sodium

Answer

To determine the metal that produces hydrogen gas when reacted with both dilute hydrochloric acid (HCl) and sodium hydroxide (NaOH), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Metals**: We need to consider the metals that are known to react with dilute hydrochloric acid and sodium hydroxide. Common metals include copper, aluminum, iron, and sodium.

2. **Test Copper**:
- When copper (Cu) is reacted with dilute hydrochloric acid, there is no reaction.
- Similarly, when copper is mixed with sodium hydroxide, there is no reaction either.
- **Conclusion**: Copper does not produce hydrogen gas in either case.

3. **Test Aluminum**:
- When aluminum (Al) reacts with dilute hydrochloric acid, it produces aluminum chloride (AlCl3) and hydrogen gas (H2).
- The reaction can be represented as:
\[ 2Al + 6HCl \rightarrow 2AlCl3 + 3H2 \]
- When aluminum reacts with sodium hydroxide, it also produces hydrogen gas:
\[ 2Al + 2NaOH + 6H2O \rightarrow 2NaAl(OH)4 + 3H2 \]
- **Conclusion**: Aluminum produces hydrogen gas in both reactions.

4. **Test Iron**:
- When iron (Fe) reacts with dilute hydrochloric acid, it produces iron(II) chloride (FeCl2) and hydrogen gas:
\[ Fe + 2HCl \rightarrow FeCl2 + H2 \]
- When iron reacts with sodium hydroxide, it also produces hydrogen gas:
\[ Fe + 2NaOH + 2H2O \rightarrow Na2Fe(OH)4 + H2 \]
- **Conclusion**: Iron also produces hydrogen gas in both reactions.

5. **Test Sodium**:
- Sodium (Na) reacts vigorously with dilute hydrochloric acid to produce sodium chloride (NaCl) and hydrogen gas:
\[ 2Na + 2HCl \rightarrow 2NaCl + H2 \]
- Sodium also reacts with sodium hydroxide, but this reaction is not typical as sodium is already a base. However, it can still produce hydrogen gas in certain conditions.
- **Conclusion**: Sodium produces hydrogen gas when reacting with hydrochloric acid.

6. **Final Conclusion**:
- The metals that produce hydrogen gas when reacted with both dilute hydrochloric acid and sodium hydroxide are aluminum, iron, and sodium.

### Answer:
The metals which produce hydrogen gas on reaction with dilute hydrochloric acid as well as sodium hydroxide solution are **aluminum, iron, and sodium**.