Consider three P, Q, R, salts among them P and Q salts have different cations annd also have different coloured polyatomic anion due to charge transfer phenomenon while P and R salts have same cation but have different anions. Salts R decomposes into an acidic gas an a basic gas.
Q. If salt Q underrgoes redox reaction with `H_(2)S` in acidic medium then which of the following speies can not be possible product?

Options

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

Explanation

To solve the question regarding the redox reaction between salt Q and H₂S in an acidic medium, we will follow these steps:

### Step 1: Identify the nature of the reaction
We are dealing with a redox reaction, which involves both oxidation and reduction processes occurring simultaneously. In this case, H₂S acts as a reducing agent.

**Hint:** Remember that in redox reactions, one species gets oxidized (loses electrons) while another gets reduced (gains electrons).

### Step 2: Determine the oxidation states
In H₂S, sulfur has an oxidation state of -2. When it acts as a reducing agent, it will be oxidized to its elemental form, which has an oxidation state of 0. Therefore, we can expect sulfur (S) to be a product of the reaction.

**Hint:** Identify the oxidation states of the elements involved to understand which species is oxidized and which is reduced.

### Step 3: Analyze salt Q
Given that salt Q contains manganese (as suggested by the presence of MnO₄²⁻ and MnO₂ in the options), we need to determine the oxidation state of manganese in these species. In MnO₄⁻, manganese is in the +7 oxidation state, while in MnO₂, it is in the +4 oxidation state.

**Hint:** Familiarize yourself with common oxidation states of transition metals, especially manganese.

### Step 4: Determine the possible products
Since H₂S is a reducing agent, it will reduce MnO₄⁻ (from +7) to a lower oxidation state, likely to Mn²⁺ (+2) in acidic medium. Therefore, MnO₄²⁻ and MnO₂ cannot be produced because they represent higher oxidation states of manganese.

**Hint:** Consider the effect of the acidic medium on the oxidation states of the reactants and products.

### Step 5: Conclusion
Based on the analysis, the species that cannot be possible products of the reaction between salt Q and H₂S in acidic medium are MnO₄²⁻ and MnO₂.

**Final Answer:** The species that cannot be possible products are MnO₄²⁻ and MnO₂.