The oxidation states of iron atoms in compounds $(A),$ $(B)$ and $(C),$ respectively,are $x,$ $y$ and $z.$ The sum of $x, y$ and $z$ is........
$(A)$ $Na_4[Fe(CN)_5(NOS)]$
$(B)$ $Na_4[FeO_4]$
$(C)$ $[Fe_2(CO)_9]$

$A$ coordination compound with the formula $FeCl_3 \cdot 4NH_3$ has a coordination number of $6$ for the central metal ion. It does not lose $NH_3$ gas upon heating but gives a white precipitate with an aqueous solution of $AgNO_3$. What is the $IUPAC$ name of this complex?

State the $IUPAC$ name of the following complex: $[Zn(NCS)_4]^{2+}$

In the brown ring complex $[Fe(H_2O)_5NO]SO_4$,the oxidation state of $Fe$ is ........

Which one of the following is tris(ethane-$1,2$-diamine)cobalt$(III)$ sulphate?

The $IUPAC$ name for the coordination compound $Ba[BrF_4]_2$ is