Aqueous solutions of `Na_(2)C_(2)O_(4)` and `CaCI_(2)` are mixed and precipitate of `CaC_(2)O_(4)` formed is filered and dried. `250 mL` of the saturated solution of `CaC_(2)O_(4)` required `6.0 mL` of `0.001M KMnO_(4)` solution in acidic medium for complete titration.
Which is the indicator in the above titration?

Options

A. Phenolphthalein
B. Methy`1` ornage
C. `KMnO_(4)` it self
D. None

Explanation

To determine the indicator used in the titration of calcium oxalate with potassium permanganate, we can follow these steps:

### Step 1: Understand the Reaction
When calcium oxalate (CaC₂O₄) is titrated with potassium permanganate (KMnO₄) in an acidic medium, the permanganate ions (MnO₄⁻) are reduced to manganese ions (Mn²⁺). The reaction can be represented as follows:

\[ \text{CaC}_2\text{O}_4 + \text{KMnO}_4 \rightarrow \text{Ca}^{2+} + \text{Mn}^{2+} + \text{CO}_2 + \text{H}_2\text{O} \]

### Step 2: Identify the Color Change
Potassium permanganate is a deep purple color due to the presence of MnO₄⁻ ions. As the titration progresses, these ions are reduced to colorless Mn²⁺ ions. The endpoint of the titration is reached when the purple color disappears, indicating that all the oxalate ions have reacted.

### Step 3: Determine the Indicator
In this case, potassium permanganate itself acts as a self-indicator. The disappearance of the purple color serves as the visual cue for the endpoint of the titration. Therefore, no additional indicator is needed.

### Conclusion
The indicator used in the titration of calcium oxalate with KMnO₄ is potassium permanganate (KMnO₄) itself.

### Final Answer
The indicator in the above titration is KMnO₄.

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