Which of the following compounds has the highest boiling point ?

Options

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

Answer

To determine which of the given compounds has the highest boiling point, we need to analyze the boiling points of the compounds based on their molecular structure and the intermolecular forces present. Here’s a step-by-step solution:

### Step 1: Identify the Compounds
The compounds in question are:
1. Acetone (CH3COCH3)
2. Diethyl ether (C2H5OC2H5)
3. Methanol (CH3OH)
4. Ethanol (C2H5OH)

### Step 2: Understand Boiling Point Factors
Boiling point is influenced by several factors:
- Molecular mass
- Surface area
- Types of intermolecular forces (hydrogen bonding, Van der Waals forces, etc.)

### Step 3: Analyze Each Compound
1. **Acetone (CH3COCH3)**:
- It has a polar carbonyl group but lacks hydrogen bonding.
- Expected to have a relatively low boiling point.

2. **Diethyl ether (C2H5OC2H5)**:
- It has an ether functional group, which allows for some dipole-dipole interactions but no hydrogen bonding.
- Expected to have a low boiling point, similar to acetone.

3. **Methanol (CH3OH)**:
- It has a hydroxyl (-OH) group, allowing for strong hydrogen bonding.
- Expected to have a higher boiling point due to hydrogen bonding.

4. **Ethanol (C2H5OH)**:
- Like methanol, it has a hydroxyl group and can also form hydrogen bonds.
- Larger molecular size compared to methanol leads to a higher boiling point due to increased surface area and stronger dispersion forces.

### Step 4: Compare Boiling Points
- Acetone and diethyl ether have lower boiling points due to the absence of hydrogen bonding.
- Methanol has a higher boiling point than both acetone and diethyl ether due to hydrogen bonding.
- Ethanol, being larger than methanol, has an even higher boiling point due to both hydrogen bonding and increased surface area.

### Conclusion
Based on the analysis, **Ethanol (C2H5OH)** has the highest boiling point among the given compounds.

### Final Answer
Ethanol has the highest boiling point.

---