Which of the following compound do not have white colour in the form of ppt ?

Options

A. `Bi_(2)S_(3)`
B. `Co[Hg(SCN)_(4)]`
C. `CdS`
D. `BiI_(3)`

Answer

To determine which of the given compounds do not form a white precipitate, we will analyze each compound one by one based on their known properties.

### Step-by-Step Solution:

1. **Identify the Compounds**: The question provides four compounds:
- Bi2S3 (Bismuth(III) sulfide)
- CoHgSCN4 (Cobalt mercuric thiocyanate)
- CdS (Cadmium sulfide)
- BiI3 (Bismuth(III) iodide)

2. **Analyze Bi2S3**:
- **Observation**: Bi2S3 is known to produce a black precipitate.
- **Conclusion**: This compound does not have a white color in the form of precipitate.

3. **Analyze CoHgSCN4**:
- **Observation**: CoHgSCN4 is known to produce a blue precipitate.
- **Conclusion**: This compound does not have a white color in the form of precipitate.

4. **Analyze CdS**:
- **Observation**: CdS is known to produce a yellow precipitate.
- **Conclusion**: This compound does not have a white color in the form of precipitate.

5. **Analyze BiI3**:
- **Observation**: BiI3 is known to produce a black precipitate.
- **Conclusion**: This compound does not have a white color in the form of precipitate.

6. **Final Conclusion**:
- Since all four compounds (Bi2S3, CoHgSCN4, CdS, and BiI3) do not produce a white precipitate, the answer is that none of the given compounds have a white color in the form of precipitate.

### Summary of Results:
- **Bi2S3**: Black precipitate
- **CoHgSCN4**: Blue precipitate
- **CdS**: Yellow precipitate
- **BiI3**: Black precipitate

### Final Answer:
All of the compounds listed (Bi2S3, CoHgSCN4, CdS, BiI3) do not have a white color in the form of precipitate.

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