What happens when a carboxylic acid is treated with lithium aluminum hydride ?

Options

A. Aldehyde is formed.
B. Primary alcohol is formed.
C. Ketone is formed.
D. Grignard reagent is formed.

Answer

To understand what happens when a carboxylic acid is treated with lithium aluminum hydride (LiAlH4), we can break down the process step by step.

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactant in this case is a carboxylic acid (RCOOH), where R represents a hydrocarbon chain or hydrogen.

2. **Recognize the Reducing Agent**:
- Lithium aluminum hydride (LiAlH4) is a strong reducing agent. It is known for its ability to reduce various functional groups, including carboxylic acids.

3. **Reduction Process**:
- When a carboxylic acid is treated with LiAlH4, the reduction process occurs in two main steps:
- **First Step**: The carboxylic acid is first reduced to an aldehyde (RCHO).
- **Second Step**: The aldehyde can further be reduced to a primary alcohol (RCH2OH).

4. **Direct Reduction to Alcohol**:
- However, since LiAlH4 is a very strong reducing agent, it can reduce the carboxylic acid directly to a primary alcohol without isolating the aldehyde. Therefore, the overall reaction can be summarized as:
\[ \text{RCOOH} + \text{LiAlH}_4 \rightarrow \text{RCH}_2\text{OH} \]
- This indicates that the carboxylic acid is converted directly into a primary alcohol.

5. **Conclusion**:
- The final product of the reaction between a carboxylic acid and lithium aluminum hydride is a primary alcohol.

### Final Answer:
When a carboxylic acid is treated with lithium aluminum hydride, it is reduced directly to a primary alcohol.

---