Write the name, the state of hybridization, the shape and the magnetic behaviour of the following complexes :
`[CoCl_(4)]^(2-),[Ni(CN_(4)]^(2-), [Cr(H_(2)O)_(2)(C_(2)O_(4))_ (2)]^(-)`
` ("At.No.": Co= 27, Ni = 28, Cr = 24)`

Explanation

`[CoCl_(4)]^(-)`: tetrachloridocobaltate (III) ion, `sp^(3)` hybridised, tetrahedral in shape, paramagnetic in nature.
`[Ni(CN)_(4)]^(2-)`: tetracyanonickelate (II) ion, `dsp^(2)` hybridised, square planar in shape, diamagnetic in nature.
`[Cr(H_(2)O)_(2)(C_(2)O_(4))_(2)]^(-)` : diaquadioxalatochromate (III) ion, `d^(2)sp^(3)` hybridised, octahedral in shape, paramagnetic in nature.