The magnetic moment of `[Mn(CN)_(6)]^(3-)` is 2.8 B.M and that of `[MnBr_(4)]^(2-)`is 5.9 B.M. What are the geometries of these complex ions

Explanation

For complex `[Mn(CN)_(6)]^(3-)`, the number of unpaired electrons is calculated as, `2.8 = sqrt(n(n+2)) implies n = 2`
`[Mn(CN)_(6)]^(3-)` has two unpaired electrons. Hence the geometry is octahedral with dsp hybridisation. For complex `[MnBr_(4)]^(2-)` the number of unpaired electrons is calculated as `5.9 = sqrt(n(n+2)) implies n=5`
`[MnBr_(4)]^(2-)`has 5 unpaired electrons. Hence the geometry is tetrahedral with `sp^(3)` hybridisation