When an acidified solution of ferrous ammonium sulphate is treated with potassium permanganate solution, the ion which is oxidised is

Options

A. `MnO_(4)^(-)`
B. `NH_(4)^(+)`
C. `Fe^(++)`
D. `SO_(4)^(2-)`

Explanation

To solve the question, we need to identify which ion is oxidized when an acidified solution of ferrous ammonium sulfate is treated with potassium permanganate solution. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Reactants
The reactants in this reaction are:
- Ferrous ammonium sulfate, which can be represented as \( \text{FeSO}_4 \cdot (NH_4)_2SO_4 \cdot 6H_2O \).
- Potassium permanganate, represented as \( \text{KMnO}_4 \).
- The solution is acidified, typically with sulfuric acid (\( \text{H}_2\text{SO}_4 \)).

### Step 2: Write the Overall Reaction
When potassium permanganate reacts with the acidified solution of ferrous ammonium sulfate, the overall reaction can be written as:
\[ 2 \text{KMnO}_4 + 8 \text{H}_2\text{SO}_4 + 10 \text{FeSO}_4 \cdot (NH_4)_2SO_4 \cdot 6H_2O \rightarrow K_2SO_4 + 2 \text{MnSO}_4 + 5 \text{Fe}_2(SO_4)_3 + 10 (NH_4)_2SO_4 + 4 \text{H}_2O \]

### Step 3: Identify the Oxidation States
- In ferrous ammonium sulfate, iron (\( \text{Fe}^{2+} \)) has an oxidation state of +2.
- In the products, iron is converted to ferric ion (\( \text{Fe}^{3+} \)), which has an oxidation state of +3.
- For manganese in potassium permanganate, the oxidation state is +7 in \( \text{MnO}_4^- \) and is reduced to +2 in \( \text{Mn}^{2+} \).

### Step 4: Determine Oxidation and Reduction
- **Oxidation** is defined as an increase in oxidation state. Here, \( \text{Fe}^{2+} \) is oxidized to \( \text{Fe}^{3+} \) (oxidation state increases from +2 to +3).
- **Reduction** is defined as a decrease in oxidation state. Here, \( \text{Mn}^{7+} \) is reduced to \( \text{Mn}^{2+} \) (oxidation state decreases from +7 to +2).

### Step 5: Conclusion
The ion that is oxidized in this reaction is \( \text{Fe}^{2+} \), as its oxidation state increases from +2 to +3.

### Final Answer
The ion which is oxidized is \( \text{Fe}^{2+} \).

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