Which among the following can exhibit cis-trans isomerism

Options

A. `CoCl_(3).4NH_(3)`
B. `CoCl_(3).6NH_(3)`
C. `CoCl_(3).5NH_(3)`
D. All of these

Answer

To determine which compounds can exhibit cis-trans isomerism, we need to analyze each compound provided in the question. Cis-trans isomerism is a type of geometrical isomerism where the arrangement of ligands around a central atom can lead to different spatial configurations.

### Step-by-step Solution:

1. **Understanding Cis-Trans Isomerism**:
- Cis-trans isomerism occurs in coordination compounds where there are two or more different ligands attached to a central metal atom. The ligands can be arranged in different spatial orientations.

2. **Analyzing Compound A: [CoCl(NH3)4(H2O)]**:
- In this compound, we have one water (H2O) ligand and one chloride (Cl) ligand, with four ammonia (NH3) ligands.
- **Cis Isomer**: The Cl and H2O ligands are adjacent to each other.
- **Trans Isomer**: The Cl and H2O ligands are opposite each other.
- **Conclusion**: Compound A can exhibit cis-trans isomerism.

3. **Analyzing Compound B: [CoCl3(NH3)3]**:
- This compound has three chloride ligands and three ammonia ligands.
- **Facial Isomer (FAC)**: All three Cl ligands are on one face of the octahedron.
- **Meridional Isomer (MER)**: The Cl ligands are arranged such that one pair is opposite each other.
- **Conclusion**: Compound B can exhibit cis-trans isomerism.

4. **Analyzing Compound C: [CoCl2(NH3)4]**:
- This compound has two chloride ligands and four ammonia ligands.
- **Cis Isomer**: Both Cl ligands are adjacent to each other.
- **Trans Isomer**: The Cl ligands are opposite each other.
- **Conclusion**: Compound C can exhibit cis-trans isomerism.

5. **Final Conclusion**:
- Since all three compounds (A, B, and C) can exhibit cis-trans isomerism, the correct answer is that all of them can show this type of isomerism.

### Final Answer:
All of the given compounds can exhibit cis-trans isomerism.