In the laboratory, manganese (II) salt is oxidized to pemanganate ion in aqueous solution by

Options

A. Hydrogen peroxide
B. Conc. Nitric acid
C. Peroxy disulphate
D. Dichromate

Explanation

To solve the problem of how manganese (II) salt is oxidized to permanganate ion in aqueous solution, we can break it down into the following steps:

### Step 1: Identify the oxidation state of manganese
Manganese in manganese (II) salt is in the +2 oxidation state (Mn²⁺).

### Step 2: Determine the target oxidation state
The target oxidation state for permanganate ion (MnO₄⁻) is +7.

### Step 3: Identify the oxidizing agent
To oxidize Mn²⁺ to MnO₄⁻, we need a strong oxidizing agent. The options provided include hydrogen peroxide, concentrated nitric acid, peroxydisulfate, and dichromate.

### Step 4: Evaluate the oxidizing agents
- **Hydrogen Peroxide (H₂O₂)**: Can act as an oxidizing agent and is known to oxidize Mn²⁺ to MnO₄⁻ in acidic conditions.
- **Concentrated Nitric Acid**: Typically oxidizes manganese but does not directly convert Mn²⁺ to MnO₄⁻.
- **Peroxydisulfate (S₂O₈²⁻)**: Is a strong oxidizing agent and can oxidize Mn²⁺ to MnO₄⁻.
- **Dichromate (Cr₂O₇²⁻)**: Also a strong oxidizing agent, but it is not typically used for this specific oxidation in aqueous solution.

### Step 5: Write the balanced reaction
When Mn²⁺ is oxidized by peroxydisulfate (S₂O₈²⁻), the reaction can be represented as follows:

\[ 2 \text{Mn}^{2+} + \text{S}_2\text{O}_8^{2-} + 8 \text{H}^+ \rightarrow 2 \text{MnO}_4^{-} + 2 \text{SO}_4^{2-} + 4 \text{H}_2\text{O} \]

### Conclusion
The correct oxidizing agent that oxidizes manganese (II) salt to permanganate ion in aqueous solution is **peroxydisulfate (S₂O₈²⁻)**.

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