Explain : `[Co(CN)_6]^(3-)` is diamagnetic while `[CoF_6]^(3-)` is paramagnetic.

Explanation

`[Co(CN)_6]^(3-)`
O.S. of CO = +3`" "`E.C. of `Co^(3+)`: `3d^6`
No. of unpaired electrons after pairing=0
Hence complexous diamagnetic
`[CoF_6]^(3-)`
O.S. of Co = +3`" "`E.C. of `Co^(3+)` : `3d^6`
No. of unpaired electrons (no pairing) = 4
Hence complex is paramagnetic.