Which of the following statements is/are correct for chromyl chloride test ?

Options

A. Formation of chromyl chloride vapour
B. Liberation of chlorine gas
C. Formation of lead chromate
D. Formation of reddis-brown vapour

Explanation

To determine which statements are correct for the chromyl chloride test, let's analyze each statement step by step.

### Step-by-Step Solution:

1. **Understanding the Chromyl Chloride Test**:
- The chromyl chloride test is used to detect the presence of chloride ions in a sample. It involves the reaction of chloride-containing salts with acidified potassium dichromate.

2. **Formation of Chromyl Chloride Vapour**:
- When a chloride salt is treated with acidified potassium dichromate, chromyl chloride (CrO2Cl2) is formed, which is known to produce red fumes.
- **Conclusion**: This statement is **correct**.

3. **Depletion of Chlorine Gas**:
- During the chromyl chloride test, chlorine gas is not produced. Instead, the chloride ions are converted into chromyl chloride.
- **Conclusion**: This statement is **incorrect**.

4. **Formation of Lead Chromate**:
- After the formation of chromyl chloride, it reacts with sodium hydroxide to produce sodium chromate (Na2CrO4), which is yellow in color. When sodium chromate is treated with acetic acid and lead acetate, lead chromate (PbCrO4) is formed, which appears as a yellow precipitate.
- **Conclusion**: This statement is **correct**.

5. **Formation of Reddish-Brown Vapour**:
- The vapours produced during the test are red, not brown. The red fumes are specifically due to the presence of chromyl chloride.
- **Conclusion**: This statement is **correct**.

### Summary of Statements:
- **Statement A**: Formation of chromyl chloride vapour - **Correct**
- **Statement B**: Depletion of chlorine gas - **Incorrect**
- **Statement C**: Formation of lead chromate - **Correct**
- **Statement D**: Formation of reddish-brown vapour - **Correct** (though it should be noted that the color is red, not brown).

### Final Answer:
The correct statements for the chromyl chloride test are:
- Formation of chromyl chloride vapour (A)
- Formation of lead chromate (C)
- Formation of reddish-brown vapour (D)