A: `MnO_(4)^(-)` is tetrahedral is shape.
R: `MnO_(4)` is purple in colour

Options

A. (1) Assertion is true, Reason is true, Reason is a correct explanation for Assertion
B. (2) Assertion is true, Reason is true, Reason is not a correct explanation for Assertion.
C. (3) Assertion is true, Reason is false
D. (4) Both assertion and Reason are false.

Answer

To solve the assertion and reason question regarding the shape and color of the permanganate ion \( \text{MnO}_4^{-} \), we can break down the solution into the following steps:

### Step 1: Analyze the Assertion
The assertion states that \( \text{MnO}_4^{-} \) is tetrahedral in shape.

- **Explanation**: The shape of \( \text{MnO}_4^{-} \) can be determined by examining its hybridization. Manganese in \( \text{MnO}_4^{-} \) has an oxidation state of +7. The hybridization involved is \( d^3s \), which leads to the formation of a tetrahedral geometry. In tetrahedral complexes, the central atom is surrounded by four atoms (in this case, four oxygen atoms) at the corners of a tetrahedron.

### Step 2: Analyze the Reason
The reason states that \( \text{MnO}_4^{-} \) is purple in color.

- **Explanation**: The purple color of \( \text{MnO}_4^{-} \) arises due to charge transfer transitions. In the case of \( \text{Mn}^{+7} \), there are no d-electrons present in the \( 3d \) orbital (as it is \( 3d^0 \)), and the color is not due to d-d transitions. Instead, the color is due to the transfer of electrons from the oxygen atoms to the manganese ion. This charge transfer results in the absorption of certain wavelengths of light, leading to the characteristic purple color.

### Step 3: Conclusion
Both the assertion and reason are correct statements, but the reason does not provide a correct explanation for the assertion.

- **Final Answer**: Both assertion and reason are correct, but the reason is not the correct explanation for the assertion.

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