Choose the incorrect statement from the following:

permanganate ion is paramagnetic in nature

The correct answer is Option (3) → permanganate ion is paramagnetic in nature

Let's analyze each statement about the permanganate ion (MnO₄⁻):

1. Permanganate ion is tetrahedral  – True, Mn is sp³ hybridized.
2. π-bonding in permanganate ion takes place by overlap of p orbital of oxygen with d orbital of manganese  – True, involves π back-bonding.
3. Permanganate ion is paramagnetic in nature  – False, Mn in +7 oxidation state has d⁰ configuration, so no unpaired electrons → diamagnetic.
4. Permanganate ion is purple in colour  – True, due to charge-transfer transition.