Which of the following does not belong to the same homologous series ?

Options

A. `CH_(4)`
B. `C_(2)H_(6)`
C. `C_(3)H_(8)`
D. `C_(4)H_(8)`

Explanation

To determine which of the given compounds does not belong to the same homologous series, we will follow these steps:

### Step 1: Understand the Concept of 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 CH2 unit in their molecular formula. For example, in the case of alkanes, the general formula is CnH2n+2.

### Step 2: Identify the Given Compounds
Let’s consider the compounds mentioned in the video transcript:
1. CH4 (Methane)
2. C2H6 (Ethane)
3. C3H8 (Propane)
4. C4H8 (Butene)

### Step 3: Analyze Each Compound
- **CH4 (Methane)**: This is the first member of the alkane series (n=1).
- **C2H6 (Ethane)**: This is the second member of the alkane series (n=2).
- **C3H8 (Propane)**: This is the third member of the alkane series (n=3).
- **C4H8 (Butene)**: This compound does not follow the alkane formula. Instead, it follows the formula for alkenes (CnH2n), which is different from the alkane series.

### Step 4: Conclusion
From the analysis, we can conclude that C4H8 (Butene) does not belong to the same homologous series as CH4, C2H6, and C3H8, which are all alkanes. Therefore, the answer is C4H8.

### Final Answer
C4H8 does not belong to the same homologous series as the other compounds listed.

---