0.56 g of limestrone was treated with oxalic acid to give `CaC_(2)O_(4)`. The precipitate decolourised 50 " mL of " `(M)/(25)` `KMnO_(4)` in acidic medium. Calculate percentage of CaO in limestone.

Explanation

To solve the problem, we need to calculate the percentage of CaO in limestone based on the given data. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Reaction
Limestone (CaCO₃) reacts with oxalic acid to form calcium oxalate (CaC₂O₄). The reaction can be summarized as:
\[ \text{CaCO}_3 + \text{Oxalic Acid} \rightarrow \text{CaC}_2\text{O}_4 + \text{CO}_2 + \text{H}_2\text{O} \]

### Step 2: Analyze the KMnO₄ Reaction
The calcium oxalate precipitate (CaC₂O₄) is then treated with KMnO₄ in acidic medium, where it gets oxidized. The balanced half-reaction for the oxidation of CaC₂O₄ is:
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