Which is/are true statement(s) when metal carbides react with `H_(2)O`?

Options

A. `AI_(4)C_(3)+H_(2)O rarr CH_(4)`
B. `CaC_(2)+H_(2)O rarr CH -= CH`
C. `Mg_(2)C_(3) + H_(2)O rarr CH_(3)C -= CH`
D. All true

Answer

To determine which statements are true when metal carbides react with water, we will analyze each statement regarding the reactions of specific metal carbides with water.

### Step-by-Step Solution:

1. **Identify the Metal Carbides**: We need to consider the reactions of different metal carbides with water. The metal carbides mentioned in the statements are aluminum carbide (Al4C3), calcium carbide (CaC2), and magnesium carbide (Mg2C3).

2. **Reaction of Aluminum Carbide (Al4C3) with Water**:
- The reaction can be represented as:
\[ \text{Al}_4\text{C}_3 + 12 \text{H}_2\text{O} \rightarrow 3 \text{CH}_4 + 2 \text{Al}_2\text{O}_3 \]
- This reaction produces methane (CH4) and aluminum oxide (Al2O3).
- **Conclusion**: This statement is true.

3. **Reaction of Calcium Carbide (CaC2) with Water**:
- The reaction can be represented as:
\[ \text{CaC}_2 + 2 \text{H}_2\text{O} \rightarrow \text{C}_2\text{H}_2 + \text{Ca(OH)}_2 \]
- This reaction produces acetylene (C2H2, also known as ethyne) and calcium hydroxide (Ca(OH)2).
- **Conclusion**: This statement is true.

4. **Reaction of Magnesium Carbide (Mg2C3) with Water**:
- The reaction can be represented as:
\[ \text{Mg}_2\text{C}_3 + 6 \text{H}_2\text{O} \rightarrow 3 \text{C}_2\text{H}_2 + 2 \text{Mg(OH)}_2 \]
- This reaction produces terminal alkynes (C2H2) and magnesium hydroxide (Mg(OH)2).
- **Conclusion**: This statement is true.

5. **Final Conclusion**:
- Since all three statements regarding the reactions of aluminum carbide, calcium carbide, and magnesium carbide with water are true, we conclude that the correct answer is:
- **All of the statements are true**.

### Final Answer:
**All of the statements are true.**

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