Two members of a homologous series have different

Options

A. general formula
B. molecular weights
C. methods of preparation
D. chemical properties.

Answer

To solve the question regarding the differences between two members of a homologous series, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Homologous Series**:
- A homologous series is a group of organic compounds that have the same functional group and similar chemical properties but differ by a specific structural unit.

2. **Identifying Members of a Homologous Series**:
- For example, consider the alkane series: Methane (CH₄), Ethane (C₂H₆), and Propane (C₃H₈). Each member differs from the next by a -CH₂- group.

3. **General Formula**:
- The general formula for alkanes is CₙH₂ₙ₊₂, where 'n' is the number of carbon atoms. As 'n' increases, the number of hydrogen atoms also increases according to this formula.

4. **Difference Between Consecutive Members**:
- The difference between two consecutive members of a homologous series can be quantified in two ways:
- **By Structural Unit**: Each consecutive member differs by one -CH₂- group.
- **By Molecular Mass**: The molecular mass increases by 14 amu (atomic mass units) for each additional -CH₂- group.

5. **Conclusion**:
- Therefore, two members of a homologous series differ by one -CH₂- group and also by a molecular mass of 14 amu.

### Final Answer:
The two members of a homologous series have different molecular masses, which differ by 14 amu.