Consider the following statements.
(I)The melting points and boiling points of aliphatic acids are usually higher than those of aromatic acids of comparable molecular masses.
(II) The planar benzene ring in the aromatic acids can pack more closely in the crystal lattice than zigzag structure of aliphatic acids.
Select the correct option.

Options

A. Only I
B. Only II
C. Both (1) and (2)
D. None of the above

Answer

To solve the question, we need to analyze the two statements provided regarding the melting points and boiling points of aliphatic and aromatic acids.

### Step-by-Step Solution:

1. **Understanding the First Statement**:
- The first statement claims that "The melting points and boiling points of aliphatic acids are usually higher than those of aromatic acids of comparable molecular masses."
- To evaluate this, we need to consider the structural differences between aliphatic and aromatic acids. Aliphatic acids have a straight-chain structure, while aromatic acids contain a benzene ring.

2. **Analyzing Melting and Boiling Points**:
- Melting and boiling points are influenced by the intermolecular forces present in the substances. Aromatic acids tend to have stronger intermolecular forces due to their planar structure, which allows for better packing in the solid state.
- As a result, aromatic acids generally exhibit higher melting and boiling points compared to aliphatic acids of similar molecular weights.

3. **Conclusion for the First Statement**:
- Since the first statement claims the opposite of what is generally observed, it is **incorrect**.

4. **Understanding the Second Statement**:
- The second statement asserts that "The planar benzene ring in the aromatic acids can pack more closely in the crystal lattice than the zigzag structure of aliphatic acids."
- The planar structure of the benzene ring allows for more efficient packing in the crystal lattice compared to the less compact zigzag structure of aliphatic acids.

5. **Conclusion for the Second Statement**:
- This statement is **correct** because the planar structure indeed allows for better packing, leading to higher melting and boiling points.

6. **Final Answer**:
- Based on the analysis, the correct option is that only the second statement is true.

### Answer:
**Only the second statement is correct.**