When propionic acid is subjected to reduction with hydroiodic acid acid Red phosphorus ,the product formed is

Options

A. Butane
B. Propane
C. Ethane
D. None of these

Answer

To solve the question regarding the reduction of propionic acid with hydroiodic acid in the presence of red phosphorus, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants are propionic acid (CH₃CH₂COOH) and hydroiodic acid (HI) in the presence of red phosphorus.

2. **Understand the Reaction Type**:
- This reaction is a reduction process. Hydroiodic acid (HI) acts as a reducing agent, and red phosphorus is often used to facilitate the reaction.

3. **Write the Structure of Propionic Acid**:
- Propionic acid can be represented as:
\[ \text{CH}_3\text{CH}_2\text{COOH} \]

4. **Reduction Mechanism**:
- When propionic acid is reduced by HI, the carboxylic acid group (-COOH) is converted to a primary alcohol (which can further be reduced to an alkane). The reduction process involves the addition of hydrogen atoms.

5. **Product Formation**:
- The reduction of propionic acid leads to the formation of propane (CH₃CH₂CH₃). The reaction can be summarized as:
\[ \text{CH}_3\text{CH}_2\text{COOH} + 2 \text{HI} \rightarrow \text{CH}_3\text{CH}_2\text{CH}_3 + 2 \text{H}_2\text{O} + 3 \text{I}_2 \]

6. **Final Product**:
- The final product formed from the reduction of propionic acid is propane (C₃H₈).

### Conclusion:
- The product formed when propionic acid is subjected to reduction with hydroiodic acid and red phosphorus is **propane (C₃H₈)**.

### Answer:
- The correct answer is **Option 2: Propane**.