The number of possible isomers of butene are

Options

A. 3
B. 2
C. 4
D. 6

Explanation

To determine the number of possible isomers of butene, we need to analyze its structure and the types of isomerism that can occur. Butene has the molecular formula C4H8.

### Step 1: Identify the Structural Isomers
Butene can exist in different structural forms. The two main structural isomers of butene are:
1. **1-Butene**: The double bond is between the first and second carbon atoms.
2. **2-Butene**: The double bond is between the second and third carbon atoms.

### Step 2: Consider Geometric Isomerism
2-Butene can further exhibit geometric (cis-trans) isomerism because the double bond restricts rotation. Therefore, we have:
- **Cis-2-butene**: The two methyl groups (CH3) are on the same side of the double bond.
- **Trans-2-butene**: The two methyl groups are on opposite sides of the double bond.

### Step 3: Count the Total Isomers
Now, let's summarize the isomers:
- 1-Butene (1 isomer)
- Cis-2-butene (1 isomer)
- Trans-2-butene (1 isomer)

Adding these together gives us:
- Total isomers = 1 (1-butene) + 1 (cis-2-butene) + 1 (trans-2-butene) = 3 isomers.

### Final Answer
The number of possible isomers of butene is **3**.

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