Methane is formed when

Options

A. sodium acetate is heated with soda lime
B. iodomethane is reduced
C. `Al_4 C_3` reacts with `H_2O`
D. All of the above

Answer

To determine when methane (CH₄) is formed, we can analyze the reactions mentioned in the video transcript. Here’s a step-by-step breakdown of the processes that lead to the formation of methane:

### Step 1: Heating Sodium Acetate with Soda Lime
1. **Reaction**: When sodium acetate (CH₃COONa) is heated with soda lime (a mixture of sodium hydroxide, NaOH, and calcium oxide, CaO), a decarboxylation reaction occurs.
2. **Products**: This reaction produces methane (CH₄) and sodium carbonate (Na₂CO₃).
- **Equation**:
\[ \text{CH}_3\text{COONa} + \text{NaOH} \xrightarrow{\Delta} \text{CH}_4 + \text{Na}_2\text{CO}_3 \]

### Step 2: Reducing Iodomethane
1. **Reaction**: Iodomethane (CH₃I) can be reduced to produce methane.
2. **Products**: The reduction of iodomethane yields methane (CH₄).
- **Equation**:
\[ \text{CH}_3\text{I} + \text{Reducing Agent} \rightarrow \text{CH}_4 + \text{Other Products} \]

### Step 3: Reaction of Aluminum Carbide with Water
1. **Reaction**: Aluminum carbide (Al₄C₃) reacts with water (H₂O).
2. **Products**: This reaction also produces methane (CH₄) along with aluminum hydroxide.
- **Equation**:
\[ \text{Al}_4\text{C}_3 + 12 \text{H}_2\text{O} \rightarrow 3 \text{CH}_4 + 4 \text{Al(OH)}_3 \]

### Conclusion
Methane is formed in the following scenarios:
- When sodium acetate is heated with soda lime.
- When iodomethane is reduced.
- When aluminum carbide reacts with water.