When `[Ni(NH_(3))_(4)]^(2+)` is treated with conc `HCI` two compounds having the formula `Ni(NH_(3))CI_(2)` (designated as I and II are formed) I can be converted into II ny boiling in dil `HCI` A solution of I reacts with oxalic acid to form `Ni(NH_(3))_(2)(C_(2)O_(4))` II does not react with oxalic acid Deduce the configuration Of I and II and the geometry of Ni (II) complexes .

Explanation

`[Ni(NH_(3))_(4)]^(2+)+HCIrarrNi (NH_(3))_(2)CI_(2)`
conc (I and II)
`I overset(dil .HCI)rarrII`
`I overset(Oxalic acid)rarrNi(NH_(3))_(2)(C_(2)O_(4))`
`I ioverset(Oxalic acid)rarr "No reaction"`
`C_(2)O_(4)^(2-)` ion is acting a bidentate ligand and forms chelate ring since I isomer of `Ni(NH_(3))_(2)CI_(2)` form `Ni(NH_(3))_(2)C_(2)O_(4)` this indicates that two `CI^(Θ)` ions in I are present at cis position

II isome of `Ni(NH_(3))_(2)CI_(2)` does not react with `C_(2)O_(4)^(2-)` ion means that the `2CI^(Θ)` are present at trans position
cis diamminedichlordonicke1(II)
trans-diamminedichloridonickel (II) .