On the basis of VBT explain the hybridization, geometrical shape and magnetic property of `[CoF_(6)]^(3-)`, hexafluorido cobaltate (III) ion.

Explanation

In this complex, the oxidation state of Co is +3. The electronic configuration of cobalt in +3 oxidation state is `[Ar]3d^(6) 4s^(0)`.
Orbitals of Cols ion are represented as

Since `F^(-)` ion provides a weak ligand fieldone 4x, three 4p and two outer 4d-orbitals hydridise to yield six `sp^(3)d^(2)` hybrid orbitals pointing towards the six corners of an octahedraon.

These six hybridised orbitals of `Co^(3+)` overlaps with orbitals of six `F^(-)` ligands and six pairs of electrons donated by six `F^(-)` to form six coordinate bonds. Six `sp^(3)d^(2)` hybrid orbitals with six pairs of electrons on ligands.
Conclusions: 1. Hybridisation-`Sp^(3),d^(2)`
2. Geometrical shape- Octahedral.
3. Magnetic property-Paramagnetic.