The following complexs are given?
trans-`[Co(NH_(3))_(4)1_(2)]^(o+)`
`cis-[Co(NH_(3))_(2)(en)_(2)]^(3+)`
trans-`[Co(NH_(3))_(2)(en)_(2)]^(3+)`
` `[Ni1_(4)]^(2-)`
`[Tif_(6)]^(2-)`
`[CoF_(6)]^(3-)`
Choose the correct code .

Options

A. `4,5` are coloured 6 is colourless
B. `2` is optically active `1,3` are optically inactive
C. `1,2` are optically active 3 optically inactive .
D. `4` is coloured, `5,6` are colourless .

Answer

To determine the optical activity of the given coordination complexes, we need to analyze each complex for the presence of symmetry elements. A complex is optically active if it lacks any symmetry elements such as a center of symmetry, plane of symmetry, or axis of symmetry. Let’s evaluate each complex step by step.

### Step 1: Analyze the first complex - trans-[Co(NH₃)₄Cl₂]⁺

1. **Identify the structure**: This is a trans octahedral complex with two chloride ligands opposite each other and four ammonia ligands.
2. **Check for symmetry**:
- The presence of two identical ligands (Cl) opposite each other indicates that there is a center of symmetry.
- Therefore, this complex has a symmetry element.
3. **Conclusion**: The first complex is **optically inactive**.

### Step 2: Analyze the second complex - cis-[Co(NH₃)₂(en)₂]³⁺

1. **Identify the structure**: This is a cis octahedral complex with two ethylenediamine (en) ligands on the same side and two ammonia ligands on the other side.
2. **Check for symmetry**:
- There are no identical ligands opposite each other, and the arrangement does not allow for a center of symmetry or any other symmetry elements.
3. **Conclusion**: The second complex is **optically active**.

### Step 3: Analyze the third complex - trans-[Co(NH₃)₂(en)₂]³⁺

1. **Identify the structure**: This is a trans octahedral complex with two ethylenediamine ligands and two ammonia ligands.
2. **Check for symmetry**:
- Similar to the first complex, the presence of two identical ligands (en) opposite each other indicates a center of symmetry.
3. **Conclusion**: The third complex is **optically inactive**.

### Step 4: Analyze the fourth complex - [NiCl₄]²⁻

1. **Identify the structure**: This is a tetrahedral complex with four chloride ligands.
2. **Check for symmetry**:
- A tetrahedral complex has no plane of symmetry or center of symmetry.
3. **Conclusion**: The fourth complex is **optically active**.

### Step 5: Analyze the fifth complex - [TiF₆]²⁻

1. **Identify the structure**: This is an octahedral complex with six fluoride ligands.
2. **Check for symmetry**:
- The presence of six identical ligands means there is a center of symmetry.
3. **Conclusion**: The fifth complex is **optically inactive**.

### Step 6: Analyze the sixth complex - [CoF₆]³⁻

1. **Identify the structure**: This is also an octahedral complex with six fluoride ligands.
2. **Check for symmetry**:
- Similar to the fifth complex, the presence of six identical ligands means there is a center of symmetry.
3. **Conclusion**: The sixth complex is **optically inactive**.

### Final Summary of Optical Activity:
- Complex 1: Optically inactive
- Complex 2: Optically active
- Complex 3: Optically inactive
- Complex 4: Optically active
- Complex 5: Optically inactive
- Complex 6: Optically inactive

### Correct Code:
Based on the analysis, the correct code is that **Complex 2 is optically active, while Complexes 1, 3, 5, and 6 are optically inactive**.