What is the oxidation state of copper in the $[Cu(NH_3)_4]^{2+}$ ion?

What is the correct $IUPAC$ name for the complex $[Co(H_2O)_4(NH_3)_2]Cl_3$?

$X$ is the number of acidic oxides among $VO_2$,$V_2O_3$,$CrO_3$,$V_2O_5$ and $Mn_2O_7$. The primary valency of cobalt in $[Co(en)_3]_2(SO_4)_3$ is $Y$. The value of $X+Y$ is $:$

The $I.U.P.A.C.$ name of ${K_3}[Ir({C_2}{O_4})_3]$ is

The $IUPAC$ name for $K[Ag(CN)_2]$ is:

State the $IUPAC$ name of the following complex: Sodium cobaltinitrite.