An acidified solution of potassium chromate was layered with an equal volume of amyl alcohol. When it was shaken after the addition of 1ml of 3% `H_2O_2,` a blue alcohol layer was obtianed. The blue color is due to the formation of a chromium (VI) compound 'X'. What is the number of oxygen atoms bonded to chromium through only single bonds in a molecule of 'X' ?

Explanation

To solve the problem, we need to analyze the formation of the chromium (VI) compound 'X' in the given reaction. Here are the steps to arrive at the solution:

### Step-by-Step Solution:

1. **Identify the Reactants**: We start with potassium chromate (K₂Cr₂O₇) in an acidified solution and add hydrogen peroxide (H₂O₂) to it. The acidification typically involves sulfuric acid (H₂SO₄).

2. **Understand the Reaction**: When potassium chromate reacts with hydrogen peroxide in an acidic medium, it forms a chromium (VI) compound. The reaction can be represented as:
\[ K_2Cr_2O_7 + H_2SO_4 + H_2O_2 \rightarrow CrO_5 + K_2SO_4 + H_2O \]
Here, CrO₅ is the chromium (VI) compound formed, which is responsible for the blue color.

3. **Determine the Structure of CrO₅**: The compound CrO₅ contains chromium in the +6 oxidation state. In CrO₅, chromium is bonded to five oxygen atoms. The structure of CrO₅ includes one chromium atom bonded to four oxygen atoms through single bonds and one oxygen atom through a double bond.

4. **Count the Single Bonds**: In CrO₅, the four oxygen atoms that are single-bonded to chromium contribute to the total count of oxygen atoms bonded to chromium through single bonds.

5. **Final Count**: Therefore, the number of oxygen atoms bonded to chromium through only single bonds in the chromium (VI) compound 'X' (which is CrO₅) is **4**.

### Conclusion:
The number of oxygen atoms bonded to chromium through only single bonds in the chromium (VI) compound 'X' is **4**.

---