Molecules whose mirror image is non-superimposable over them are known as chiral. Which of the following molecules is chiral in nature?

Options

A. 2-bromobutane
B. 1-bromobutane
C. 2-bromopropane
D. 2-bromopropan-2-ol

Explanation

To determine which of the given molecules is chiral, we need to analyze each option based on the definition of chirality. A molecule is considered chiral if it has a carbon atom that is bonded to four different substituents, making its mirror image non-superimposable over itself.

### Step-by-Step Solution:

1. **Understanding Chirality**:
- A chiral molecule has a carbon atom with four different groups attached to it. This results in a non-superimposable mirror image.

2. **Analyzing the Options**:
- We will consider each option and check for the presence of a chiral carbon.

3. **Option 1: 1,2-bromobutane**:
- Structure: CH3-CHBr-CH2-CH3
- The carbon attached to bromine (C1) has the following substituents:
- CH3 (methyl group)
- CH2CH3 (ethyl group)
- H (hydrogen)
- Br (bromine)
- All four substituents are different.
- **Conclusion**: This molecule is chiral.

4. **Option 2: 1-bromobutane**:
- Structure: CH3-CH2-CH2-CHBr
- The carbon attached to bromine (C4) has:
- CH3 (methyl group)
- CH2CH2 (ethyl group)
- H (hydrogen)
- H (another hydrogen)
- Here, two substituents are the same (two hydrogens).
- **Conclusion**: This molecule is not chiral.

5. **Option 3: 2-bromopropane**:
- Structure: CH3-CHBr-CH3
- The carbon attached to bromine (C2) has:
- CH3 (methyl group)
- CH3 (another methyl group)
- H (hydrogen)
- Br (bromine)
- Again, two substituents are the same (two methyl groups).
- **Conclusion**: This molecule is not chiral.

6. **Option 4: 2-bromopropan-2-ol**:
- Structure: CH3-C(OH)(Br)-CH3
- The carbon attached to both bromine and hydroxyl (C2) has:
- CH3 (methyl group)
- CH3 (another methyl group)
- OH (hydroxyl group)
- Br (bromine)
- Here, two substituents are the same (two methyl groups).
- **Conclusion**: This molecule is not chiral.

7. **Final Conclusion**:
- The only chiral molecule among the options is **1,2-bromobutane** (Option 1).

### Summary:
The chiral molecule is **1,2-bromobutane**.

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