Chemistry - Carbonyl compounds Question with Solution | TestHub

In${\mathrm{\text{K}}}_3\left[\mathrm{\text{C}}\mathrm{\text{o}}{\left(\mathrm{\text{C}}{\mathrm{\text{O}}}_3\right)}_3\right],$cobalt shows the +3 oxidation state i.e.,$\left({\text{d}}^6\right)$ion. Hence, Co (+3) has four unpaired electrons so, it is paramagnetic.

The magnetic moment of Co(+3)

In${\mathrm{\text{K}}}_3\left[\mathrm{\text{C}}\mathrm{\text{o}}{\left(\mathrm{\text{C}}{\mathrm{\text{O}}}_3\right)}_3\right]=\sqrt{\text{n}\left(\text{n}+2\right)}\mathrm{\text{B}}\mathrm{\text{M}}$

$=\sqrt{4\left(4+2\right)}$BM=4.9 BM

Where, n=number of unpaired electrons

$\mathrm{\text{C}}{\mathrm{\text{O}}}_3^{2-}$is a weak field bidentate ligand, so$3\mathrm{\text{C}}{\mathrm{\text{O}}}_3^{2-}$ligands occupy six orbitals, thus it shows$\text{s}{\text{p}}^3{\text{d}}^2$hybridisation and octahedral in shape.