Discuss the formation of `[Ni(NH_(3))_(4)]^(2+)` with the help of valence bond theory.

Explanation

`[Ni(NH_(3))_(4)]^(2+)` ion is formed by the reaction of `Ni^(2+)` ion with `NH_(3)` molecules. `Ni^(2+)(3d^(8))` ion undergoes `sp^(3)-` hybridisation and the hybrid orbitals are directed towards the four corners of tetrahedron. The hybrid orbitals acceptas 4 lone pairs of electron from 4 `NH_(3)` molecules by forming 4 coordinate bonds, which leads to the formation of tetrahedral `[Ni(NH_(3))_(4)]^(2+)` ion.

The compound contains 2 unpaired electrons in its valence shell and hence shows paramagnetism.