An anhybride and an ester can be distinguished with

Options

A. `C_2H_5OH`
B. `NH_3`
C. water
D. aqueous NaOH

Answer

To distinguish between an anhydride and an ester, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Compounds**:
- An anhydride has the general formula R-C(O)-O-C(O)-R, where R represents alkyl groups.
- An ester has the general formula R-C(O)-O-R', where R and R' are alkyl groups.

2. **Adding Water**:
- Take two separate beakers: one containing the anhydride and the other containing the ester.
- Add water to both beakers. This process is known as hydrolysis.

3. **Observing the Reactions**:
- In the beaker with the anhydride, hydrolysis will produce a carboxylic acid (RCOOH).
- In the beaker with the ester, hydrolysis will produce a carboxylic acid (RCOOH) and an alcohol (R'OH).

4. **Testing with Litmus Paper**:
- Take blue litmus paper and dip it into the solution from the beaker with the anhydride.
- If the blue litmus paper turns red, this indicates the presence of an acid (from the hydrolysis of the anhydride).
- Now, take the blue litmus paper and dip it into the solution from the beaker with the ester.
- The litmus paper should remain unchanged, indicating that the solution is neutral (due to the presence of the alcohol).

5. **Conclusion**:
- If the blue litmus paper turns red, you have identified the anhydride.
- If the blue litmus paper does not change color, you have identified the ester.

### Final Answer:
An anhydride and an ester can be distinguished by adding water and using blue litmus paper. The anhydride will turn the blue litmus paper red, while the ester will not change the color of the litmus paper.