An example of a compound with a functional group - O - is

Options

A. Acetic acid
B. Ethanol
C. Diethyl ether
D. Methyl acetate.

Answer

To find an example of a compound with a functional group containing -O, we will analyze the given options one by one.

### Step-by-Step Solution:

1. **Identify the Functional Group**: We are looking for a compound that contains the functional group -O. This could refer to ether (-O-), alcohol (-OH), or carbonyl groups (C=O).

2. **Evaluate Acetic Acid**:
- The structure of acetic acid (CH3COOH) shows that it has a carboxylic acid functional group (C=O and -OH).
- However, it does not have the ether functional group (-O-).
- **Conclusion**: Acetic acid is not the correct answer.

3. **Evaluate Ethanol**:
- The structure of ethanol (C2H5OH) shows it has an alcohol functional group (-OH).
- It does not contain the ether functional group (-O-).
- **Conclusion**: Ethanol is not the correct answer.

4. **Evaluate Diethyl Ether**:
- The structure of diethyl ether (C2H5OC2H5) shows that it contains the ether functional group (-O-).
- This matches our requirement for a compound with the functional group -O.
- **Conclusion**: Diethyl ether is a valid example.

5. **Evaluate Methyl Acetate**:
- The structure of methyl acetate (C3H6O2) shows it has a carbonyl group (C=O) and an ether-like structure (C-O).
- However, it is primarily classified as an ester, not an ether.
- **Conclusion**: Methyl acetate is not the correct answer.

6. **Final Answer**: The compound with the functional group -O is **Diethyl Ether**.