Assertion (A): Following are the members of a homologous series `CH_(3)OH, CH_(3),CH_(2),OH, CH_(3),CH_(2),CH_(2)OH`
Reason (R): A series of compounds with same functional group but differing by-`CH_(2)`, - unit is called a homologous series.

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is NOT the correct explanation of A.
C. A is true but R is false.
D. A is false and R is true.

Answer

**Step-by-Step Solution:**

1. **Understanding the Assertion (A)**:
- The assertion states that the compounds `CH₃OH`, `CH₃CH₂OH`, and `CH₃CH₂CH₂OH` are members of a homologous series.
- A homologous series is a group of organic compounds that have the same functional group and differ from each other by a constant unit, typically `-CH₂-`.

2. **Identifying the Functional Group**:
- In the given compounds, the functional group is the `-OH` (hydroxyl) group, which indicates that these compounds are alcohols.
- The first compound `CH₃OH` is methanol, the second `CH₃CH₂OH` is ethanol, and the third `CH₃CH₂CH₂OH` is propanol.

3. **Checking the Differences**:
- To confirm they are part of a homologous series, we check the difference between successive members:
- From `CH₃OH` (methanol) to `CH₃CH₂OH` (ethanol), we add one `-CH₂-` unit.
- From `CH₃CH₂OH` (ethanol) to `CH₃CH₂CH₂OH` (propanol), we again add one `-CH₂-` unit.
- This confirms that the compounds differ by a `-CH₂-` unit.

4. **Understanding the Reason (R)**:
- The reason states that a series of compounds with the same functional group but differing by `-CH₂-` units is called a homologous series.
- This definition aligns with the properties of the compounds listed in the assertion.

5. **Conclusion**:
- Both the assertion (A) and the reason (R) are true.
- The reason (R) correctly explains the assertion (A).

**Final Answer**: Both A and R are true, and R is the correct explanation of A.

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