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 question regarding the changes that 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 break it down into a series of logical steps.

### Step-by-Step Solution:

1. **Identify the Reactants and Their Properties**:
- The reactants are the dichromate ion \( \text{Cr}_2\text{O}_7^{2-} \) and hydrogen peroxide \( \text{H}_2\text{O}_2 \).
- The dichromate ion is known to be orange in color and has chromium in the +6 oxidation state.

2. **Reaction Conditions**:
- The reaction takes place in an acidified medium, typically using sulfuric acid \( \text{H}_2\text{SO}_4 \), which helps facilitate the reaction.
- The presence of ether solvent suggests that the reaction may involve the formation of a specific product that is soluble in ether.

3. **Product Formation**:
- When \( \text{Cr}_2\text{O}_7^{2-} \) reacts with \( \text{H}_2\text{O}_2 \), it forms \( \text{CrO}_5 \) (chromium pentoxide), which is a blue compound.
- The color change from orange to blue indicates a significant transformation in the solution.

4. **Oxidation State Analysis**:
- To determine the oxidation state of chromium in \( \text{CrO}_5 \), we can analyze the structure:
- In \( \text{CrO}_5 \), there are peroxide linkages (where oxygen has an oxidation state of -1) and double-bonded oxygen (where oxygen has an oxidation state of -2).
- The overall charge of \( \text{CrO}_5 \) must equal zero. Let the oxidation state of chromium be \( x \):
\[ x + 4(-1) + (-2) = 0 \implies x - 4 - 2 = 0 \implies x = +6 \]
- Thus, the oxidation state of chromium remains +6 throughout the reaction.

5. **Conclusion**:
- The orange color of the solution turns blue due to the formation of \( \text{CrO}_5 \).
- The oxidation state of chromium does not change; it remains +6 before and after the reaction.

### 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.