The formula of the deep red liquid formed on warming dichromate with KCI in concentrated sulphuric acid is _____.

Explanation

To determine the formula of the deep red liquid formed when potassium dichromate (K2Cr2O7) reacts with potassium chloride (KCl) in the presence of concentrated sulfuric acid (H2SO4), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants in this reaction are potassium dichromate (K2Cr2O7) and potassium chloride (KCl), along with concentrated sulfuric acid (H2SO4).

2. **Understand the Reaction Conditions**:
- The reaction occurs upon warming the mixture of potassium dichromate and potassium chloride in concentrated sulfuric acid.

3. **Write the Reaction Equation**:
- The main products formed from this reaction are chromyl chloride (CrO2Cl2), potassium sulfate (K2SO4), and water (H2O). The balanced chemical equation for the reaction is:
\[ K2Cr2O7 + 4 KCl + 3 H2SO4 \rightarrow 2 CrO2Cl2 + 3 K2SO4 + 3 H2O \]

4. **Identify the Deep Red Liquid**:
- Among the products, chromyl chloride (CrO2Cl2) is known for its deep red color and is the compound we are interested in.

5. **Conclude the Formula**:
- Therefore, the formula of the deep red liquid formed on warming dichromate with KCl in concentrated sulfuric acid is **CrO2Cl2**.

### Final Answer:
The formula of the deep red liquid formed on warming dichromate with KCl in concentrated sulfuric acid is **CrO2Cl2**.