`KMnO_(4)` acts as an oxidising agent in

Options

A. Acidic medium only
B. Neutral and acidic medium
C. Neutral and alkaline medium
D. Neutral, acidic and fairly basic medium

Answer

To determine the conditions under which KMnO₄ acts as an oxidizing agent, we need to analyze its behavior in different media: acidic, neutral, and basic. Let's break this down step by step.

### Step 1: Identify the oxidation state of manganese in KMnO₄
In KMnO₄, the oxidation state of manganese (Mn) is +7. This is the highest oxidation state that manganese can exhibit.

**Hint:** Remember that the oxidation state of an element in a compound can indicate its ability to act as an oxidizing agent.

### Step 2: Understand the definition of an oxidizing agent
An oxidizing agent is a substance that can accept electrons from another substance, thereby oxidizing it. In the process, the oxidizing agent itself gets reduced. Since KMnO₄ has manganese in the +7 oxidation state, it can readily accept electrons.

**Hint:** An oxidizing agent is characterized by its ability to be reduced while causing oxidation in another substance.

### Step 3: Analyze the behavior of KMnO₄ in different media
- **In acidic medium:** KMnO₄ (Mn +7) is reduced to Mn²⁺ (Mn +2).
- **In neutral medium:** KMnO₄ is reduced to MnO₂ (Mn +4).
- **In alkaline medium:** KMnO₄ is reduced to MnO₄²⁻ (Mn +6).

**Hint:** The reduction products of KMnO₄ vary depending on the pH of the solution, but it can act as an oxidizing agent in all these conditions.

### Step 4: Conclusion
Since KMnO₄ can act as an oxidizing agent in acidic, neutral, and alkaline media, the correct answer to the question is that KMnO₄ acts as an oxidizing agent in all three media.

**Final Answer:** KMnO₄ acts as an oxidizing agent in acidic, neutral, and alkaline medium.