Decarboxylation of isobutyric acid yields

Options

A. Isobutane
B. 2-Methylpropane
C. n-Butane
D. Propane

Answer

To solve the question regarding the decarboxylation of isobutyric acid, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of Isobutyric Acid**:
- Isobutyric acid (also known as 2-methylpropanoic acid) has the following structure:
\[ \text{CH}_3\text{C}(\text{COOH})\text{CH}_3 \]
- This can be represented as:
\[ \text{CH}_3 - \text{C}(\text{OH}) - \text{CH}_3 \]
- Here, the carboxylic acid functional group (-COOH) is attached to the second carbon of the isobutyl group.

2. **Understand the Decarboxylation Process**:
- Decarboxylation is the process of removing a carboxyl group (-COOH) from a compound, resulting in the release of carbon dioxide (CO₂).
- The general reaction can be summarized as:
\[ \text{RCOOH} \rightarrow \text{RH} + \text{CO}_2 \]
- In this case, the carboxyl group from isobutyric acid will be removed, and a hydrogen atom will be added to the carbon atom that was previously bonded to the carboxyl group.

3. **Perform the Decarboxylation Reaction**:
- When isobutyric acid undergoes decarboxylation, the structure changes as follows:
- The carboxyl group (-COOH) is removed, and the remaining carbon atom will gain a hydrogen atom.
- The resulting structure after decarboxylation will be:
\[ \text{CH}_3 - \text{CH}_2 - \text{CH}_3 \]
- This is the structure of propane.

4. **Identify the Product**:
- The product formed from the decarboxylation of isobutyric acid is propane (C₃H₈).

5. **Select the Correct Option**:
- Based on the options provided, the correct answer is the compound propane, which corresponds to option number 4.

### Final Answer:
The decarboxylation of isobutyric acid yields propane (C₃H₈).

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