Chromyl chloride test is given by -

Options

A. `CH_(3)Cl`
B. `AgCl`
C. `Hg_(2)Cl_(2)`
D. `NH_(4)Cl`

Answer

To solve the question regarding which compound gives a chromyl chloride test, we will analyze each option based on their ability to generate free chloride ions. The chromyl chloride test is indicated by the presence of the compound CrO2Cl2 (chromyl chloride), which is formed when certain chloride-containing compounds release free chloride ions.

### Step-by-Step Solution:

1. **Understanding Chromyl Chloride Test**:
- The chromyl chloride test is performed to identify compounds that can generate free chloride ions (Cl⁻) in solution. The presence of free chloride ions is essential for the formation of chromyl chloride (CrO2Cl2).

2. **Analyzing the Options**:
- We will evaluate each compound to determine if it can dissociate to release free chloride ions.

3. **Option A: CH3Cl (Methyl chloride)**:
- CH3Cl is a partially ionic and partially covalent compound.
- In normal conditions, it does not dissociate into CH3⁺ and Cl⁻ ions effectively.
- **Conclusion**: CH3Cl does not give a positive chromyl chloride test.

4. **Option B: AgCl (Silver chloride)**:
- AgCl is also a partially covalent compound.
- It does not dissociate into Ag⁺ and Cl⁻ ions in solution under normal conditions.
- **Conclusion**: AgCl does not give a positive chromyl chloride test.

5. **Option C: Hg2Cl2 (Mercurous chloride)**:
- Hg2Cl2 is a partially covalent compound as well.
- Similar to AgCl, it does not dissociate into Hg²⁺ and Cl⁻ ions effectively.
- **Conclusion**: Hg2Cl2 does not give a positive chromyl chloride test.

6. **Option D: NH4Cl (Ammonium chloride)**:
- NH4Cl is a proper ionic compound.
- It dissociates completely in solution into NH4⁺ and Cl⁻ ions.
- **Conclusion**: NH4Cl does give a positive chromyl chloride test because it generates free chloride ions.

7. **Final Answer**:
- The compound that gives a positive chromyl chloride test is **Option D: NH4Cl**.