The oxidation state of $Fe$ in $K_3[Fe(CN)_6]$ is .......

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 $(0)$

The $IUPAC$ name for the complex $[Co(NH_3)_5(NO_2)]Cl_2$ is:

The oxidation number of cobalt in $K[Co(CO)_4]$ is:

In ammonium phosphomolybdate,the oxidation state of $Mo$ is $..........$.

The oxidation state of the metal in the complex ion $[PtCl_6]^{2-}$ is....