Predict the number of unpaired electrons in the square planar `[Pt(CN)_(4)]^(2-)` ion.

Explanation

Electronic configuration of `Pt=5d^(9)6s^(1), Pt^(2+)=5d^(8)6s^(0)`.

In order to form square planar complex, the required hybridiation is `dsp^(2)`. Thus in presence of `CN^(-)` ions (strong ligand), the unpaired electrons in 5d orbital of `Pt^(2+)` pair up to empty a d - orbital. So there will be no unpaired electrons in the 5d - orbital. So there will be no unpaired electrons in the 5d - orbitals of `Pt^(2+)` in the tetracyano complex.

Thus `[Pt(CN)_(4)]^(2-)` does not exhibit paramagnetism.