Which of the following is/are correct statement (s):

Options

A. The number of structural isomers for molecular formula `C_(3)H_(8)` are `2`
B. The number of structural isomers for molecular formula `C_(5)H_(12)` are `3`
C. The number of structural isomers for molecular formula `C_(6)H_(14)` are `5`
D. The number of benzene ring containing structral isomers for molecular formula `C_(6)H_(4)BrCl` are `4`

Explanation

To solve the question regarding which statements about structural isomers are correct, we will analyze each molecular formula provided and determine the number of structural isomers for each.

### Step-by-Step Solution:

1. **Understanding Structural Isomers**:
- Structural isomers are compounds that have the same molecular formula but different structural arrangements of atoms.

2. **Analyzing C3H8 (Propane)**:
- The molecular formula C3H8 corresponds to propane.
- The only structural isomer for C3H8 is straight-chain propane itself (CH3-CH2-CH3).
- Therefore, the number of structural isomers for C3H8 is **1**.
- **Conclusion**: The statement regarding C3H8 is incorrect.

3. **Analyzing C5H12 (Pentane)**:
- The molecular formula C5H12 corresponds to pentane.
- The structural isomers for C5H12 include:
1. **n-pentane** (CH3-CH2-CH2-CH2-CH3)
2. **Isopentane** (2-methylbutane)
3. **Neopentane** (2,2-dimethylpropane)
- Therefore, the number of structural isomers for C5H12 is **3**.
- **Conclusion**: The statement regarding C5H12 is correct.

4. **Analyzing C6H14 (Hexane)**:
- The molecular formula C6H14 corresponds to hexane.
- The structural isomers for C6H14 include:
1. **n-hexane**
2. **2-methylpentane**
3. **3-methylpentane**
4. **2,2-dimethylbutane**
5. **2,3-dimethylbutane**
6. **3,3-dimethylbutane**
- Therefore, the number of structural isomers for C6H14 is **5**.
- **Conclusion**: The statement regarding C6H14 is correct.

5. **Analyzing Benzene Derivatives**:
- For a benzene ring with two substituents (e.g., bromine and chlorine), the possible structural isomers are:
1. **Ortho (1,2-)**
2. **Meta (1,3-)**
3. **Para (1,4-)**
- Therefore, the number of structural isomers for a benzene ring with two different substituents is **3**.
- **Conclusion**: The statement regarding benzene derivatives is correct.

### Final Summary:
- The correct statements are:
- The number of structural isomers for C5H12 is 3.
- The number of structural isomers for C6H14 is 5.
- The number of benzene ring containing structural isomers is 3.

Thus, the correct statements are the ones regarding C5H12, C6H14, and benzene derivatives.