`K_(2)Cr_(2)O_(7) + "conc" H_(2)SO_(4)+ H_(2)O_(2) ether rarr ` blue precipitate anbydride (in enthereal layer) Blue colour is due to

Options

A. `CrO_(3)`
B. `H_(2)CrO_(4)`
C. `H_(2)Cr_(2)O_(3)`
D. `CrO_(5)`

Answer

To solve the question regarding the reaction of potassium dichromate (K₂Cr₂O₇) with concentrated sulfuric acid (H₂SO₄) and hydrogen peroxide (H₂O₂) in the presence of ether, we will analyze the process step by step.

### Step-by-Step Solution:

1. **Identify the Reactants**:
The reactants in the reaction are potassium dichromate (K₂Cr₂O₇), concentrated sulfuric acid (H₂SO₄), hydrogen peroxide (H₂O₂), and ether.

2. **Understanding the Reaction**:
When potassium dichromate is treated with concentrated sulfuric acid and hydrogen peroxide, a redox reaction occurs. Hydrogen peroxide acts as an oxidizing agent, while the chromium in potassium dichromate is reduced.

3. **Oxidation States**:
In potassium dichromate, chromium is in the +6 oxidation state. When it reacts with hydrogen peroxide, it gets reduced to a lower oxidation state. The hydrogen peroxide (H₂O₂) itself gets oxidized during this process.

4. **Formation of Products**:
The products of this reaction include chromium pentoxide (CrO₅), potassium sulfate (K₂SO₄), and water (H₂O). The reaction can be summarized as:
\[ K₂Cr₂O₇ + 4 H₂O₂ + 4 H₂SO₄ \rightarrow 2 CrO₅ + K₂SO₄ + 4 H₂O \]

5. **Color of the Product**:
The key product of interest is chromium pentoxide (CrO₅), which is known to have a blue color. This blue color is due to the presence of the CrO₅ compound formed in the reaction.

6. **Conclusion**:
Therefore, the blue precipitate observed in the ethereal layer is due to the formation of chromium pentoxide (CrO₅).

### Final Answer:
The blue color is due to **CrO₅**.