The difference in molecular weights of two consecutive members of a homologous series is

Options

A. 14
B. 2
C. 4
D. 8

Explanation

To find the difference in molecular weights of two consecutive 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 constant unit, typically a -CH2- group.

2. **Identifying the Difference**:
- The difference between two consecutive members of a homologous series is represented by the addition of one -CH2- group. This means that for each step in the series, we add a -CH2- unit.

3. **Calculating the Molecular Weight of -CH2**:
- To find the molecular weight of the -CH2- group, we need to consider the atomic weights of carbon (C) and hydrogen (H).
- The atomic weight of carbon (C) is approximately 12 g/mol.
- The atomic weight of hydrogen (H) is approximately 1 g/mol.

4. **Calculating the Total for -CH2**:
- The molecular weight of -CH2 can be calculated as follows:
- Molecular weight of -CH2 = (1 × Atomic weight of C) + (2 × Atomic weight of H)
- = (1 × 12) + (2 × 1)
- = 12 + 2
- = 14 g/mol.

5. **Conclusion**:
- Therefore, the difference in molecular weights of two consecutive members of a homologous series is 14 g/mol.

### Final Answer:
The difference in molecular weights of two consecutive members of a homologous series is **14 g/mol**.

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