Which of the following statements is wrong for homologous series?

Options

A. (a) All members have a general formula.
B. (b) All members have the same functional group.
C. (c) All members have the same chemical properties.
D. (d) All members have the same physical properties.

Explanation

To determine which statement is wrong regarding homologous series, we need to analyze each statement based on the characteristics of homologous series in organic chemistry.

### Step-by-Step Solution:

1. **Understanding Homologous Series**:
- A homologous series is a group of organic compounds that share a common functional group and have the same general formula. The members of this series differ from each other by a constant unit, typically a -CH2- group.

2. **Analyzing the Statements**:
- **Statement 1**: "All members have the same general formula."
- This statement is **correct**. All members of a homologous series do indeed have the same general formula.

- **Statement 2**: "All members have the same functional group."
- This statement is also **correct**. Since the compounds in a homologous series differ only by the -CH2- group, they maintain the same functional group.

- **Statement 3**: "All members have the same chemical properties."
- This statement is **correct**. The chemical properties are largely determined by the functional group, which remains constant in a homologous series.

- **Statement 4**: "All members have the same physical properties."
- This statement is **incorrect**. While the functional group is the same, the physical properties (such as boiling point, melting point, and solubility) can vary due to differences in molecular mass and structure among the members of the series.

3. **Conclusion**:
- The statement that is wrong for homologous series is **Statement 4**: "All members have the same physical properties."

### Final Answer:
The wrong statement for homologous series is: **"All members have the same physical properties."**

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