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Question
KMnO4 is coloured due to ______.
Options
d-d transitions
charge transfer from ligand to metal
unpaired electrons in d orbital of Mn
charge transfer from metal to ligand
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Solution
KMnO4 is coloured due to charge transfer from ligand to metal.
Explanation:
The Mn atom in KMnO4 has a +7 oxidation state with electron configuration [Ar]3d04s0. Since no unpaired electrons are present, d−d transitions are not possible. The molecule should, therefore, be colourless.
Its intense purple due to `"L"→"M"` (ligand to metal) charge transfer 2p(L) of O to 3d(M) of Mn.
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