Which of the following will not give positive chromyl chloride test ?

Options

A. Copper chloride, `CuCl_(2)`
B. Mercuric chloride, `HgCl_(2)`
C. Zinc chloride, `ZnCl_(2)`
D. Anilinium chloride `C_(6)H_(5)NH_(3)Cl`

Explanation

To determine which of the given compounds will not give a positive chromyl chloride test, we need to understand the nature of the compounds and the chromyl chloride test itself.

### Step-by-Step Solution:

1. **Understand the Chromyl Chloride Test**:
- The chromyl chloride test is used to detect the presence of chloride ions (Cl⁻) in inorganic salts.
- The test involves the reaction of a chloride salt with potassium dichromate (K₂Cr₂O₇) and dilute sulfuric acid (H₂SO₄) upon heating, which produces chromyl chloride (CrO₂Cl₂) and other products.

2. **Identify the Compounds**:
- The compounds given in the question are:
- Copper chloride (CuCl₂)
- Mercurous chloride (Hg₂Cl₂)
- Zinc chloride (ZnCl₂)
- Anilinium chloride (C₆H₅NH₃Cl)

3. **Analyze Each Compound**:
- **Copper Chloride (CuCl₂)**: This is an ionic compound that dissociates into Cu²⁺ and Cl⁻ ions in solution. It will give a positive chromyl chloride test.
- **Mercurous Chloride (Hg₂Cl₂)**: This compound is primarily covalent in nature and does not dissociate into Cl⁻ ions in solution. Therefore, it will not give a positive chromyl chloride test.
- **Zinc Chloride (ZnCl₂)**: This is also an ionic compound that dissociates into Zn²⁺ and Cl⁻ ions. It will give a positive chromyl chloride test.
- **Anilinium Chloride (C₆H₅NH₃Cl)**: This compound is ionic as well, dissociating into C₆H₅NH₃⁺ and Cl⁻ ions. It will also give a positive chromyl chloride test.

4. **Conclusion**:
- Among the given options, mercurous chloride (Hg₂Cl₂) is the only compound that will not give a positive chromyl chloride test due to its covalent nature.

### Final Answer:
The compound that will not give a positive chromyl chloride test is **Mercurous Chloride (Hg₂Cl₂)**.