When dilute `H_(2)SO_(4) and H_(2)O_(2)` are added to a solution of chromate ions, an intense blue colour is produced, which is stable in ether. Theis is due to the formation of

Options

A. `Cr_(2)O_(7)^(2-)`
B. `Cr_(2)O_(3)`
C. `CrO_(5)`
D. `CrO_(3)`

Answer

To solve the question regarding the formation of an intense blue color when dilute H₂SO₄ and H₂O₂ are added to a solution of chromate ions, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this scenario are chromate ions (CrO₄²⁻), dilute sulfuric acid (H₂SO₄), and hydrogen peroxide (H₂O₂).

2. **Understand the Reaction Conditions**: The presence of dilute sulfuric acid indicates that the reaction occurs in an acidic medium. Hydrogen peroxide acts as an oxidizing agent.

3. **Write the Reaction**: When chromate ions are treated with hydrogen peroxide in an acidic medium, a reaction occurs that leads to the formation of a new compound. The reaction can be represented as:
\[ \text{CrO}_4^{2-} + \text{H}_2\text{O}_2 + \text{H}_2\text{SO}_4 \rightarrow \text{CrO}_5 + \text{H}_2\text{O} \]

4. **Identify the Product**: The product formed in this reaction is CrO₅ (chromium pentoxide). This compound is known to exhibit an intense blue color.

5. **Stability of the Product**: The blue color of CrO₅ is stable in ether, which is a non-polar solvent. This characteristic is important as it indicates the solubility and stability of the compound in different solvents.

6. **Conclusion**: Therefore, the intense blue color observed is due to the formation of CrO₅ when dilute H₂SO₄ and H₂O₂ are added to a solution of chromate ions.

### Final Answer:
The intense blue color is due to the formation of **CrO₅**.

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