In order to oxidise a mixture of one mole of each of `FeC_(2)O_(4),Fe_(2)(C_(2)O_(4))_(3),FeSO_(4) and Fe_(2)(SO_(4))_(3)` in acidic medium, the number of moles of `KMnO_(4)` required is :

Options

A. 2
B. 1
C. 1.5
D. 3

Answer

To determine the number of moles of KMnO₄ required to oxidize the given mixture of compounds in acidic medium, we will analyze each compound and calculate the total moles of KMnO₄ needed.

### Step 1: Identify the oxidation states and reactions

1. **Ferrous Oxalate (FeC₂O₄)**:
- Contains 1 mole of Fe²⁺ and 1 mole of C₂O₄²⁻.
- The oxidation of Fe²⁺ to Fe³⁺ requires 1 electron.
- The oxidation of C₂O₄²⁻ to CO₂ involves the conversion of carbon from +3 to +4 oxidation state, which requires 2 electrons (1 electron per carbon atom).

2. **Ferric Oxalate (Fe₂(C₂O₄)₃)**:
- Contains 2 moles of Fe³⁺ and 3 moles of C₂O₄²⁻.
- Since Fe³⁺ is already in a higher oxidation state, it does not participate in the oxidation reaction.
- The oxidation of 3 moles of C₂O₄²⁻ to CO₂ will require 6 electrons.

3. **Ferrous Sulfate (FeSO₄)**:
- Contains 1 mole of Fe²⁺ and 1 mole of SO₄²⁻.
- The oxidation of Fe²⁺ to Fe³⁺ requires 1 electron.

4. **Ferric Sulfate (Fe₂(SO₄)₃)**:
- Contains 2 moles of Fe³⁺ and 3 moles of SO₄²⁻.
- Similar to ferric oxalate, Fe³⁺ does not participate in the oxidation reaction.

### Step 2: Calculate total moles of electrons required

- From **Ferrous Oxalate**:
- Fe²⁺: 1 mole requires 1 electron.
- C₂O₄²⁻: 1 mole requires 2 electrons.
- Total from FeC₂O₄ = 1 + 2 = 3 electrons.

- From **Ferric Oxalate**:
- C₂O₄²⁻: 3 moles require 6 electrons.
- Total from Fe₂(C₂O₄)₃ = 6 electrons.

- From **Ferrous Sulfate**:
- Fe²⁺: 1 mole requires 1 electron.
- Total from FeSO₄ = 1 electron.

- From **Ferric Sulfate**:
- No contribution since Fe³⁺ does not oxidize.

### Step 3: Total moles of electrons required

Total electrons required = 3 (from FeC₂O₄) + 6 (from Fe₂(C₂O₄)₃) + 1 (from FeSO₄) = 10 electrons.

### Step 4: Determine moles of KMnO₄ required

- Each mole of KMnO₄ (MnO₄⁻) can accept 5 electrons when reduced to Mn²⁺.
- Therefore, the number of moles of KMnO₄ required = Total electrons required / 5 = 10 / 5 = 2 moles.

### Final Answer

The number of moles of KMnO₄ required to oxidize the mixture is **2 moles**.

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