Without considering stereoisomers the number of possible
structural isomers of dibromobutane is

Options

A. 5
B. 9
C. 3
D. 8

Explanation

To determine the number of possible structural isomers of dibromobutane (C4H8Br2), we can follow these steps:

### Step 1: Identify the Parent Hydrocarbon
The parent hydrocarbon for dibromobutane is butane (C4H10). The structure of butane can be represented as:
- CH3-CH2-CH2-CH3

### Step 2: Determine the Positions for Bromine Substitution
Since we are considering dibromobutane, we need to place two bromine atoms on the butane structure. The bromine atoms can be placed on different carbon atoms in various combinations.

### Step 3: List Possible Structural Isomers
We will systematically place the bromine atoms on different carbon atoms:

1. **1,1-Dibromobutane**:
- CH3-CH2-C(Br)(Br)-CH3

2. **1,2-Dibromobutane**:
- CH3-CH(Br)-CH(Br)-CH3

3. **1,3-Dibromobutane**:
- CH3-CH(Br)-CH2-CH(Br)-CH3

4. **1,4-Dibromobutane**:
- CH3-CH2-CH2-C(Br)(Br)-CH3

5. **2,2-Dibromobutane**:
- CH3-C(Br)(Br)-CH2-CH3

6. **2,3-Dibromobutane**:
- CH3-CH(Br)-C(Br)-CH3

7. **3,3-Dibromobutane**:
- CH3-CH2-C(Br)(Br)-CH3

### Step 4: Count the Unique Isomers
Now, we count the unique structural isomers we have listed:
1. 1,1-Dibromobutane
2. 1,2-Dibromobutane
3. 1,3-Dibromobutane
4. 1,4-Dibromobutane
5. 2,2-Dibromobutane
6. 2,3-Dibromobutane
7. 3,3-Dibromobutane

### Conclusion
The total number of structural isomers of dibromobutane is **6**.

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