Which out of the following compounds will liberate methane upon reaction with water?

Options

A. `BeC_(2)`
B. `Al_(4)C_(3)`
C. `Be_(2)C`
D. Both (B) and (C)

Explanation

To determine which compound will liberate methane (CH4) upon reaction with water, we need to analyze the compounds mentioned in the question.

### Step-by-Step Solution:

1. **Identify the Compounds**:
The compounds mentioned in the video transcript are:
- Be(OH)2
- Al(OH)3
- C2H2 (ethyne or acetylene)

2. **Reaction with Water**:
We need to consider how each of these compounds reacts with water:
- **Be(OH)2**: Beryllium hydroxide does not liberate methane when it reacts with water.
- **Al(OH)3**: Aluminum hydroxide also does not liberate methane upon reaction with water.
- **C2H2 (ethyne)**: Ethyne can react with water under certain conditions to produce methane.

3. **Chemical Reaction**:
The reaction of ethyne with water can be represented as:
\[ C_2H_2 + H_2O \rightarrow CH_4 + CO \]
This reaction shows that ethyne can indeed liberate methane when it reacts with water.

4. **Conclusion**:
Among the compounds listed, **C2H2 (ethyne)** is the compound that will liberate methane upon reaction with water.

### Final Answer:
**C2H2 (ethyne)** will liberate methane upon reaction with water.

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