If salt Q undergoes redox reaction with `H_(2)S` in acidic medium then which of the following species can not be possible product?

Options

A. `MnO_(4)^(2-)(aq.)`
B. `S`
C. `MnO_(2)`
D. both (a) and (c)

Explanation

To determine which species cannot be a product of the redox reaction between salt Q and H₂S in an acidic medium, we will analyze the possible reactions and the oxidation states involved.

### Step-by-Step Solution:

1. **Identify the Reactants**:
- We have salt Q and H₂S. In acidic medium, H₂S can act as a reducing agent.

2. **Determine the Oxidation States**:
- In H₂S, sulfur (S) has an oxidation state of -2.
- In the presence of an acidic medium, H₂S can be oxidized to sulfur (S) with an oxidation state of 0.

3. **Identify the Salt**:
- Let's assume salt Q is MnO₄⁻ (manganate ion), which contains manganese in the +7 oxidation state.

4. **Write the Half-Reactions**:
- **Oxidation Half-Reaction**:
\[ H₂S \rightarrow S + 2H^+ + 2e^- \]
- **Reduction Half-Reaction**:
\[ MnO₄^- + 8H^+ + 5e^- \rightarrow Mn^{2+} + 4H₂O \]

5. **Balance the Overall Reaction**:
- To balance the number of electrons, we can multiply the oxidation half-reaction by 5:
\[ 5H₂S \rightarrow 5S + 10H^+ + 10e^- \]
- Now, we can combine the two half-reactions:
\[ 5H₂S + MnO₄^- + 8H^+ \rightarrow 5S + Mn^{2+} + 4H₂O + 10e^- \]

6. **Identify Possible Products**:
- From the balanced reaction, we see that the products are sulfur (S) and manganese ions (Mn²⁺).

7. **Determine Which Species Cannot Be a Product**:
- Given the options (not provided in the transcript), we need to identify which of the proposed products does not appear in our balanced reaction.
- Since we have identified sulfur and manganese ions as products, any species that does not correspond to these products or any other common oxidation states of sulfur or manganese in acidic conditions would not be a possible product.

8. **Conclusion**:
- The species that cannot be a product of this reaction would be those that do not match the expected products from the balanced equation.