What product is formed when acetic acid heated with `P_(2)O_(5)`

Options

A. Acetyl chloride
B. Acetate ester
C. Acetic anhydride
D. Acetaldehyde

Answer

To determine the product formed when acetic acid is heated with phosphorus pentoxide (P₂O₅), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactant in this case is acetic acid, which has the chemical formula CH₃COOH.

2. **Understand the Role of P₂O₅**:
Phosphorus pentoxide (P₂O₅) acts as a dehydrating agent. This means it will remove water (H₂O) from the reaction mixture.

3. **Write the Chemical Reaction**:
When two molecules of acetic acid are heated with P₂O₅, the reaction can be represented as:
\[ 2 \text{CH}_3\text{COOH} \xrightarrow{\text{P}_2\text{O}_5} \text{Product} + \text{H}_2\text{O} \]

4. **Remove Water from the Acetic Acid**:
In the reaction, one molecule of water is removed. The hydroxyl group (-OH) from one acetic acid molecule and a hydrogen atom (H) from another acetic acid molecule combine to form water. The remaining parts of the acetic acids will combine to form a new compound.

5. **Determine the Product**:
After the removal of water, the remaining parts of the two acetic acid molecules combine to form acetic anhydride. The structure of acetic anhydride can be represented as:
\[ \text{CH}_3\text{COO}\text{CH}_3 \]
or more commonly as:
\[ \text{(CH}_3\text{CO)}_2\text{O} \]

6. **Final Product**:
The final product of the reaction is acetic anhydride.

### Conclusion:
When acetic acid is heated with phosphorus pentoxide (P₂O₅), the product formed is **acetic anhydride**.