Which type of isomerism is shown by `[Co(NH_(3))_(4)Br_(2)]Cl`

Options

A. geometrical and ionisation
B. Optical and lonisation
C. Geometrical and Optical
D. Geometrical only

Answer

To determine the type of isomerism shown by the complex `[Co(NH₃)₄Br₂]Cl`, we will analyze the complex step by step.

### Step 1: Identify the Coordination Complex
The given complex is `[Co(NH₃)₄Br₂]Cl`. Here, cobalt (Co) is the central metal atom, and it is coordinated with four ammonia (NH₃) ligands and two bromide (Br) ligands. The chloride (Cl) ion is outside the coordination sphere.

### Step 2: Determine Possible Types of Isomerism
In coordination chemistry, there are several types of isomerism, but we will focus on three main types relevant to this complex:
1. **Geometric Isomerism (Cis-Trans Isomerism)**
2. **Ionization Isomerism**
3. **Optical Isomerism**

### Step 3: Analyze Geometric Isomerism
- **Geometric Isomerism** occurs when ligands can be arranged differently around the central metal atom.
- For the complex `[Co(NH₃)₄Br₂]`, we can have:
- **Cis Isomer**: Both Br ligands are adjacent to each other.
- **Trans Isomer**: The Br ligands are opposite each other.

Since we have two types of arrangements (cis and trans), this complex exhibits geometric isomerism.

### Step 4: Analyze Ionization Isomerism
- **Ionization Isomerism** occurs when the ligands can exchange places with ions outside the coordination sphere.
- In this case, the chloride ion (Cl) is outside the coordination sphere. We can form an ionization isomer by switching the positions of the bromide and chloride ions.
- For example, we can have `[Co(NH₃)₄BrCl]Br` as an ionization isomer, where one bromide ion is now outside the coordination sphere.

### Step 5: Analyze Optical Isomerism
- **Optical Isomerism** occurs when a complex can exist in two non-superimposable mirror images (enantiomers).
- In this case, the presence of two identical ligands (Br) means that the complex does not have a chiral center. Therefore, it cannot exhibit optical isomerism.

### Conclusion
Based on the analysis:
- The complex `[Co(NH₃)₄Br₂]Cl` exhibits **Geometric Isomerism** (cis-trans) and **Ionization Isomerism** (due to the presence of the chloride ion outside the coordination sphere).
- Therefore, the answer is that the complex shows both **Geometric and Ionization Isomerism**.

### Final Answer
The complex `[Co(NH₃)₄Br₂]Cl` shows **Geometric Isomerism and Ionization Isomerism**.

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