Choose the correct statement regarding the physical properties of carbonyl compound.

Options

A. All aldehydes are insoluble in benzene.
B. Higher aldehydes are more fragrant.
C. n - Butane has more boiling point than acetone.
D. Methanal and propanone are immiscible with water in all proportions.

Answer

To solve the question regarding the physical properties of carbonyl compounds, we need to evaluate each of the provided statements and determine which one is correct. Let's analyze them step by step.

### Step 1: Analyze the Options

1. **Option 1: All aldehydes are insoluble in benzene.**
- This statement is incorrect. Aldehydes are generally soluble in benzene because they do not require hydrogen bonding with benzene, unlike water.

2. **Option 2: Higher aldehydes are more fragrant.**
- This statement is correct. Lower aldehydes often have unpleasant odors, while as the size of the aldehyde increases, the odor becomes less pungent and more fragrant.

3. **Option 3: N-butane has a higher boiling point than acetone.**
- This statement is incorrect. Acetone, being a polar compound with a carbonyl group, has stronger intermolecular forces (dipole-dipole interactions) compared to nonpolar n-butane, leading to a higher boiling point for acetone.

4. **Option 4: Aldehydes are soluble in water up to four carbon atoms.**
- This statement is partially correct but does not directly answer the question about carbonyl compounds in general. It is also misleading as it implies that all aldehydes are soluble in water, which is not the case for higher aldehydes.

### Conclusion

After analyzing all the options, the correct statement regarding the physical properties of carbonyl compounds is:

**Option 2: Higher aldehydes are more fragrant.**