Which of the following molecule is chiral.

Options

A.
B.
C.
D.

Answer

To determine which of the given molecules is chiral, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Identify the Molecules**: We have four options to evaluate for chirality. Let's denote them as:
- Option A: Cyclopropane with ClHClHClH
- Option B: Cyclobutane with HNCl
- Option C: Cyclohexane with Br and Cl
- Option D: A molecule with Br and Cl both outside the plane.

2. **Analyze Option A (Cyclopropane)**:
- **Structure**: Cyclopropane is a three-membered ring.
- **Symmetry Check**: When we cut the molecule in half, we can see that both halves are identical. There is a plane of symmetry present.
- **Conclusion**: Cyclopropane is **not chiral**.

**Hint**: Look for a plane of symmetry to determine if a molecule is chiral.

3. **Analyze Option B (Cyclobutane)**:
- **Structure**: Cyclobutane is a four-membered ring.
- **Symmetry Check**: Similar to cyclopropane, when we divide the molecule, both halves are the same. A plane of symmetry exists.
- **Conclusion**: Cyclobutane is **not chiral**.

**Hint**: Check for identical halves when dividing the molecule.

4. **Analyze Option C (Cyclohexane)**:
- **Structure**: Cyclohexane with Br and Cl positioned differently.
- **Symmetry Check**: If we cut the molecule, we find that the left and right sides are identical, indicating a plane of symmetry.
- **Conclusion**: Cyclohexane is **not chiral**.

**Hint**: Look for symmetry in the arrangement of substituents.

5. **Analyze Option D (Br and Cl both outside the plane)**:
- **Structure**: This molecule has Br and Cl both positioned outside the plane.
- **Symmetry Check**: When we analyze this structure, we find that there is no plane of symmetry present. The arrangement of Br and Cl creates a non-superimposable mirror image.
- **Conclusion**: This molecule is **chiral**.

**Hint**: A lack of symmetry often indicates chirality.

### Final Conclusion:
Only **Option D** is the chiral compound among the given options. The other options (A, B, and C) are non-chiral due to the presence of symmetry.