Which of the following is correct about Tetraamminedithiocyanato-s cobalt(III) tris(oxalato)cobaltate(III)?

Options

A. Formula of the complex is `[Co(SCN)_(2)(NH_(3))_(4)][Co(o x)_(3)]`
B. It is a chelating complex and show linkage isomerism
C. it shows optical isomerism
D. it shows geometrical isomerism

Explanation

To determine the correct statements about Tetraamminedithiocyanato-cobalt(III) tris(oxalato)cobaltate(III), we need to analyze the coordination compound step by step.

### Step 1: Identify the components of the coordination compound
The compound is composed of:
- Tetraammine (NH3) ligands
- Dithiocyanato (SCN) ligands
- Cobalt(III) ion (Co³⁺)
- Tris(oxalato) (C2O4²⁻) ligands

### Step 2: Determine the charges of the ligands and the central metal ions
1. **Tetraammine (NH3)**: Neutral ligand, contributes 0 charge.
2. **Dithiocyanato (SCN)**: Each SCN ligand has a charge of -1. Since there are 2 SCN ligands, the total charge contributed by SCN is -2.
3. **Oxalato (C2O4²⁻)**: Each oxalato ligand has a charge of -2. Since there are 3 oxalato ligands, the total charge contributed by oxalato is -6.
4. **Cobalt(III) ion (Co³⁺)**: The cobalt ion has a charge of +3.

### Step 3: Calculate the overall charge of the coordination complex
The overall charge of the complex can be calculated as follows:
- Cationic part (from cobalt): +3 (from Co³⁺)
- Anionic part (from ligands): -2 (from 2 SCN) + -6 (from 3 oxalato) = -8

The overall charge of the coordination complex is:
\[ +3 + (-8) = -5 \]

### Step 4: Analyze the statements regarding the coordination compound
1. **Statement about the charge**: If the statement claims that the cobaltate has a charge of -6, it is incorrect because the overall charge is -5.

2. **Chelating complex**: The presence of oxalato ligands (which are bidentate) indicates that the complex is indeed a chelating complex.

3. **Linkage isomerism**: The dithiocyanato ligands can bond through sulfur or nitrogen, indicating that linkage isomerism is possible.

4. **Optical activity**: The structure can exhibit optical activity due to the arrangement of the ligands, which can lead to non-superimposable mirror images.

5. **Geometrical isomerism**: The presence of different arrangements of the ligands (cis and trans) indicates that geometrical isomerism is also possible.

### Conclusion
Based on the analysis:
- The first statement about the charge is incorrect.
- The other statements regarding chelation, linkage isomerism, optical activity, and geometrical isomerism are correct.

### Final Answer
The correct statements about Tetraamminedithiocyanato-cobalt(III) tris(oxalato)cobaltate(III) are:
- It is a chelating complex.
- It shows linkage isomerism.
- It is optically active.
- It shows geometrical isomerism.