The purple colour of `KMnO_(4)` is due to

Options

A. Charge transfer
B. d-d transition
C. f-f transition
D. d-f transition

Explanation

To determine the reason behind the purple color of potassium permanganate (KMnO₄), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Compound**:
- We are analyzing potassium permanganate, KMnO₄.

2. **Determine the Oxidation State of Manganese (Mn)**:
- In KMnO₄, the oxidation state of Mn is +7. This can be calculated by considering the charges of potassium (K⁺) and four oxygen atoms (O²⁻).

3. **Examine the Electronic Configuration of Mn**:
- The electronic configuration of Mn in the +7 oxidation state is [Ar] 3d⁰ 4s⁰. This indicates that there are no d-electrons in the 3d subshell.

4. **Understand Color Origin in Transition Metal Complexes**:
- The color in transition metal complexes often arises from d-d transitions, where electrons move between d-orbitals. However, in this case, since Mn is in the +7 state, it has no d-electrons available for such transitions.

5. **Consider Ligand to Metal Charge Transfer (LMCT)**:
- The purple color of KMnO₄ is primarily due to ligand to metal charge transfer (LMCT). In this process, electrons from the ligand (in this case, oxygen) are transferred to the metal (Mn).

6. **Conclude the Reason for the Color**:
- Therefore, the purple color of KMnO₄ is attributed to the charge transfer from the ligand (oxygen) to the metal (manganese).

### Final Answer:
The purple color of KMnO₄ is due to ligand to metal charge transfer (LMCT).

---