Assertion (A) In the reaction between potassium permanganate and potassium iodide, permanganate ions acts as oxidising agent.
Reason ( R) Oxidation state of manganese changes from +2 and +7 during the reaction.

Options

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is not the correct explanation of A
C. A is true but R is false
D. Both A and R are false

Explanation

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that in the reaction between potassium permanganate (KMnO4) and potassium iodide (KI), the permanganate ion (MnO4^-) acts as an oxidizing agent.

**Explanation:**
- An oxidizing agent is a substance that gains electrons in a chemical reaction and is reduced in the process.
- In the reaction between KMnO4 and KI, the permanganate ion (MnO4^-) indeed acts as an oxidizing agent because it facilitates the oxidation of iodide ions (I^-) to iodine (I2) while itself being reduced.

### Step 2: Analyze the Reason
The reason states that the oxidation state of manganese changes from +2 to +7 during the reaction.

**Explanation:**
- In KMnO4, manganese has an oxidation state of +7.
- In the product MnSO4, manganese has an oxidation state of +2.
- Therefore, the oxidation state of manganese changes from +7 to +2, not from +2 to +7 as stated in the reason.

### Step 3: Conclusion
- The assertion is true: KMnO4 acts as an oxidizing agent.
- The reason is false: the oxidation state of manganese changes from +7 to +2, not the other way around.

### Final Answer
The correct conclusion is that the assertion is true, but the reason is false. Therefore, the answer is option 3: "Assertion is true but reason is false."

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