What changes occur when acidified `Cr_(2)O_(7)^(2-)` ion react with `H_(2)O_(2)` solution in presence of ether solvent?

Options

A. Orange colour of solution turns blue
B. Oxidation state of Cr-atom decrease
C. Oxidation state of Cr-atom remains constant
D. Orange colour of solution turns green

Answer

To solve the problem of what changes occur when acidified \( \text{Cr}_2\text{O}_7^{2-} \) ion reacts with \( \text{H}_2\text{O}_2 \) solution in the presence of ether solvent, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- The reactants in this reaction are the acidified dichromate ion \( \text{Cr}_2\text{O}_7^{2-} \) and hydrogen peroxide \( \text{H}_2\text{O}_2 \).
- The acidification is typically done using sulfuric acid \( \text{H}_2\text{SO}_4 \).

2. **Color of the Dichromate Ion**:
- The dichromate ion \( \text{Cr}_2\text{O}_7^{2-} \) is known to have an orange color in solution.

3. **Reaction with Hydrogen Peroxide**:
- When \( \text{H}_2\text{O}_2 \) is added to the acidified dichromate solution, a redox reaction occurs.
- In this reaction, the dichromate ion acts as an oxidizing agent.

4. **Formation of Product**:
- The product formed from this reaction is \( \text{CrO}_5 \) (chromium pentoxide), which is a deep blue color.
- This transformation is significant as it indicates a change in the oxidation state of chromium.

5. **Oxidation State of Chromium**:
- In both \( \text{Cr}_2\text{O}_7^{2-} \) and \( \text{CrO}_5 \), chromium is in the +6 oxidation state.
- Therefore, the oxidation state of chromium remains constant throughout the reaction.

6. **Summary of Changes**:
- The orange color of the solution (due to \( \text{Cr}_2\text{O}_7^{2-} \)) changes to deep blue (due to \( \text{CrO}_5 \)).
- The oxidation state of chromium does not change; it remains +6.

### Final Answer:
- The changes that occur are:
1. The orange color of the solution turns blue.
2. The oxidation state of chromium remains constant at +6.