Why heavy metal chlorides such as `Hg_(2)Cl_(2), AgCl, PbCl_(2)` etc. do not respond to chromyl chloride test.

Explanation

### Step-by-Step Solution:

1. **Understanding the Chromyl Chloride Test**:
- The chromyl chloride test is a qualitative analysis method used to detect chloride ions (Cl⁻) in a sample.
- In this test, potassium dichromate (K₂Cr₂O₇) is used in the presence of concentrated sulfuric acid (H₂SO₄).

2. **Reaction Mechanism**:
- When chloride ions are present, they react with potassium dichromate and concentrated sulfuric acid to produce chromyl chloride (CrO₂Cl₂) as an orange-red vapor.
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