What is the oxidation number of $Fe$ in $K_3[Fe(CN)_6]$?

The $IUPAC$ name of $[Ni(NH_3)_4][NiCl_4]$ is

Identify the formula of Bis(ethylenediamine)dithiocyanatoplatinum$(IV)$.

Write the formulas for the following coordination compounds:
$(a)$ Tetraammineaquachloridocobalt $(III)$ chloride
$(b)$ Potassium tetrahydroxidozincate $(II)$
$(c)$ Potassium trioxalatoaluminate $(III)$
$(d)$ Dichloridobis(ethane$-1,2-$diamine)cobalt $(III)$
$(e)$ Tetracarbonylnickel $(0)$

What is the oxidation state of cobalt in $[Co(NH_3)_6]^{3+}$?

Which among the following will be named as dibromidobis(ethylenediamine)chromium$(III)$ bromide?