Acetylene can be prepared from

Options

A. potassium fumerate
B. calcium carbide
C. ethylene bromide
D. all of these.

Answer

To determine how acetylene can be prepared from the given compounds, we will analyze each compound and the reactions involved.

### Step-by-Step Solution:

1. **Potassium Fumarate**:
- Potassium fumarate has the formula \( \text{C}_4\text{H}_4\text{O}_4\text{K}_2 \).
- When subjected to electrolysis, it undergoes a reaction that produces acetylene (C2H2) along with carbon dioxide (CO2), potassium hydroxide (KOH), and hydrogen (H2).
- The reaction can be summarized as:
\[ \text{Potassium Fumarate} \xrightarrow{\text{Electrolysis}} \text{Acetylene} + 2 \text{CO}_2 + 2 \text{KOH} + \text{H}_2 \]
- From this reaction, we see that 1 mole of acetylene is produced.

2. **Calcium Carbide**:
- Calcium carbide has the formula \( \text{CaC}_2 \).
- When calcium carbide reacts with water, it produces calcium hydroxide (Ca(OH)2) and acetylene.
- The reaction can be summarized as:
\[ \text{CaC}_2 + 2 \text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 + \text{C}_2\text{H}_2 \]
- Again, we see that 1 mole of acetylene is produced from this reaction.

3. **Ethylene Bromide**:
- Ethylene bromide has the formula \( \text{C}_2\text{H}_2\text{Br}_2 \).
- When it reacts with potassium hydroxide (KOH), it undergoes a dehydrohalogenation reaction to produce acetylene.
- The reaction can be summarized as:
\[ \text{C}_2\text{H}_2\text{Br}_2 + 2 \text{KOH} \rightarrow \text{C}_2\text{H}_2 + 2 \text{KBr} + 2 \text{H}_2\text{O} \]
- This reaction also yields 1 mole of acetylene.

### Conclusion:
From the analysis of the three compounds, we conclude that acetylene can be prepared from:
- Potassium Fumarate
- Calcium Carbide
- Ethylene Bromide

Thus, acetylene can be prepared from all of these compounds.