The alkane formed on heating sodium butanoate with soda lime is

Options

A. ethane
B. propane
C. butane
D. methane

Explanation

To solve the problem of determining the alkane formed when sodium butanoate is heated with soda lime, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of Sodium Butanoate**:
Sodium butanoate is the sodium salt of butanoic acid. The structure can be represented as:
\[ \text{CH}_3\text{CH}_2\text{CH}_2\text{COO}^- \text{Na}^+ \]
This indicates that sodium butanoate contains 4 carbon atoms.

2. **Understand the Reaction with Soda Lime**:
Soda lime is a mixture of sodium hydroxide (NaOH) and calcium oxide (CaO). When sodium butanoate is heated with soda lime, a reaction known as decarboxylation occurs. This process involves the removal of the carboxyl group (-COOH) from the compound.

3. **Decarboxylation Process**:
During decarboxylation, the carboxyl group (-COO) is removed, releasing carbon dioxide (CO2) and resulting in the formation of an alkane. The reaction can be represented as:
\[ \text{CH}_3\text{CH}_2\text{CH}_2\text{COO}^- \text{Na}^+ \rightarrow \text{C}_n\text{H}_{2n+2} + \text{CO}_2 + \text{Na}_2\text{CO}_3 \]
Here, one carbon atom is lost from the original 4-carbon compound.

4. **Determine the Alkane Formed**:
After the removal of one carbon atom from butanoate (4 carbons), we are left with 3 carbon atoms. The alkane with 3 carbon atoms is propane (C3H8).

5. **Conclusion**:
Therefore, the alkane formed on heating sodium butanoate with soda lime is propane.

### Final Answer:
The alkane formed is **propane**.

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