An isomer of ethanol is

Options

A. Methanol
B. Diethyl ether
C. Acetone
D. Dimethyl ether

Explanation

To determine an isomer of ethanol, we first need to understand what ethanol is and what isomers are.

1. **Identify Ethanol**:
Ethanol is a simple alcohol with the molecular formula C2H5OH. This means it contains 2 carbon atoms, 6 hydrogen atoms, and 1 oxygen atom.

2. **Understanding Isomers**:
Isomers are compounds that have the same molecular formula but different structural formulas. There are different types of isomers, including structural isomers and functional isomers.

3. **Finding Isomers of Ethanol**:
Since ethanol is an alcohol, we can look for its functional isomers. The functional isomer of an alcohol can be an ether.

4. **Identifying Possible Isomers**:
- **Methanol (C1H3OH)**: This is not an isomer of ethanol because it has a different molecular formula.
- **Diethyl Ether (C4H10O)**: This has a different molecular formula and is not an isomer.
- **Acetone (C3H6O)**: This is also not an isomer of ethanol due to a different molecular formula.
- **Dimethyl Ether (C2H6O)**: This has the same molecular formula as ethanol (C2H6O) and is a functional isomer.

5. **Conclusion**:
The isomer of ethanol is **Dimethyl Ether (C2H6O)**.

### Summary of Steps:
1. Identify the molecular formula of ethanol (C2H5OH).
2. Understand the concept of isomers.
3. Look for potential isomers with the same molecular formula.
4. Evaluate each option to find the correct isomer.
5. Conclude that Dimethyl Ether is the isomer of ethanol.