When intimate mixture of potassium dichromate and potassium chloride is heated with conc.`H_(2)SO_(4)` which of the following is produced in the form of red vapours ?

Options

A. `CrO_(3)`
B. `Cr_(2)O_(3)`
C. `CrO_(2)Cl_(2)`
D. `CrCl_(2)`

Answer

To solve the question, we need to analyze the reaction between potassium dichromate (K₂Cr₂O₇), potassium chloride (KCl), and concentrated sulfuric acid (H₂SO₄). Here's a step-by-step breakdown of the solution:

### Step 1: Identify the Reactants
The reactants in this reaction are:
- Potassium dichromate (K₂Cr₂O₇)
- Potassium chloride (KCl)
- Concentrated sulfuric acid (H₂SO₄)

### Step 2: Write the Reaction Equation
When potassium dichromate is heated with potassium chloride and concentrated sulfuric acid, the following reaction occurs:
\[ K_2Cr_2O_7 + 4 KCl + 3 H_2SO_4 \rightarrow 2 CrO_2Cl_2 + K_2SO_4 + 3 H_2O \]

### Step 3: Identify the Product
From the balanced equation, the main product of interest is chromyl chloride (CrO₂Cl₂). This compound is known to produce red vapors when formed.

### Step 4: Analyze the Options
Now, we need to check which of the given options corresponds to the product formed:
1. CrO₃ - Not formed in this reaction.
2. Cr₂O₃ - Not formed in this reaction.
3. CrO₂Cl₂ - This is the correct product that produces red vapors.
4. CrCl₂ - Not formed in this reaction.

### Conclusion
The correct answer is **CrO₂Cl₂**, which is chromyl chloride that produces red vapors.

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