In solid $CuSO_4 \cdot 5H_2O$,copper is coordinated to:

Which of the following configurations will show an outer orbital octahedral complex?

The pair$(s)$ of complexes wherein both exhibit tetrahedral geometry is(are):
Note: $py = \text{pyridine}$
Given: Atomic numbers of $Fe, Co, Ni$ and $Cu$ are $26, 27, 28$ and $29$,respectively.
$(A)$ $[FeCl_4]^-$ and $[Fe(CO)_4]^{2-}$
$(B)$ $[Co(CO)_4]^-$ and $[CoCl_4]^{2-}$
$(C)$ $[Ni(CO)_4]$ and $[Ni(CN)_4]^{2-}$
$(D)$ $[Cu(py)_4]^+$ and $[Cu(CN)_4]^{3-}$

Pick out the correct statement with respect to $[Mn(CN)_6]^{3-}.$

In a square planar complex of $Co^{2+}$ ion,the unpaired electron is present in which orbital?

The geometry and magnetic behaviour of the complex $[Ni(CO)_4]$ are