The oxidation state of $Co$ in $K[Co(CO)_4]$ is

Write the formulas for the following coordination compounds:
$(i)$ Tetraamminediaquacobalt$(III)$ chloride
$(ii)$ Potassium tetracyanidonickelate$(II)$
$(iii)$ Tris(ethane$-1,2-$diamine)chromium$(III)$ chloride
$(iv)$ Amminebromidochloridonitrito$-N-$platinate$(II)$
$(v)$ Dichloridobis(ethane$-1,2-$diamine)platinum$(IV)$ nitrate
$(vi)$ Iron$(III)$ hexacyanidoferrate$(II)$

Which one is the correct formula for the coordination compound tris(ethane-$1,2$-diamine) cobalt$(III)$ sulphate?

The correct formula of potassium ferrocyanide is:

The oxidation state of iron in $Na_{4}[Fe(CN)_{5}(NOS)]$ is

The oxidation number of $Pt$ in $[Pt(C_2H_4)Cl_3]^{-}$ is