What product is formed when `H_2S` gas is passed through acidified `KMnO_4` solution ?

Options

A. `MnO_2`
B. S
C. `K_2SO_3`
D. `K_2S`

Answer

To determine the product formed when hydrogen sulfide (H₂S) gas is passed through acidified potassium permanganate (KMnO₄) solution, we can follow these steps:

### Step 1: Understand the Reaction Conditions
When H₂S is passed through acidified KMnO₄, the KMnO₄ acts as an oxidizing agent. It is typically acidified using sulfuric acid (H₂SO₄).

### Step 2: Write the Balanced Chemical Equation
The balanced chemical equation for the reaction can be represented as follows:

\[ 2 \text{KMnO}_4 + 3 \text{H}_2\text{SO}_4 + 5 \text{H}_2\text{S} \rightarrow 2 \text{MnSO}_4 + K_2\text{SO}_4 + 8 \text{H}_2\text{O} + 5 \text{S} \]

### Step 3: Identify the Products
From the balanced equation, we can identify the products formed:
- Manganese(II) sulfate (MnSO₄)
- Potassium sulfate (K₂SO₄)
- Water (H₂O)
- Elemental sulfur (S)

### Step 4: Determine the Oxidation States
- In H₂S, sulfur (S) has an oxidation state of -2.
- In the products, sulfur is present as elemental sulfur (S), which has an oxidation state of 0.
- KMnO₄ contains manganese (Mn) in the +7 oxidation state, which is reduced to +2 in MnSO₄.

### Conclusion
The main product of the reaction when H₂S is oxidized by acidified KMnO₄ is elemental sulfur (S).

### Final Answer
The product formed when H₂S gas is passed through acidified KMnO₄ solution is **sulfur (S)**.

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