Question

The IUPAC name of $[Ni{(N{H_3})_4}][NiC{l_4}]$ is :
A. $tetrachloro nickel(II) - tetraamine nickel(II)$
B. $tetrammine nickel(II) - tetrachloro nickel(II)$
C. $tetraamine nickel(II) - tetrachloronickelate(II)$
D. $tetrachloro nickel(II) - tetraammine nickelate(0)$

Answer 1

In order to identify the correct IUPAC name we must know some key points while naming coordination compounds. Naming coordination compounds includes a set of rules which means that the oxidation number of the central ion and the chemical composition of the ligand and focusing on the anionic and cationic properties of the molecule.

Complete step-by-step answer: Coordination compounds contain an ion and an array of ligands. These compounds can be neutral or charged. When it is charged, it is stabilized by neighboring counter-ions.
While naming a transition-metal compound, it is necessary to indicate in which oxidation number the metal is. In $[Ni{(N{H_3})_4}][NiC{l_4}]$ the ligand $N{H_3}$ is neutral so has zero oxidation state and ligand Chlorine has $- 4$
So , oxidation number of Nickel $= \dfrac{4}{2} = 2$ which is represented in roman number as $(II)$
In $[Ni{(N{H_3})_4}][NiC{l_4}]$, the first cationic part of the complex is named and afterwards the anionic part is named.
The name of the metal present in the complex anion ends in suffix '-ate'. The prefix tetra indicates the presence of four chlorine ligands or four ammonia ligands.

Hence option C is correct where the IUPAC name is $tetraamine nickel(II) - tetrachloronickelate(II)$.

Note: The atom which is present within a ligand that is bonded to the central atom or ion is called the donor atom. More complicated coordination compounds consist of an atom or ion which is usually a metal and a surrounding array of bound molecules or anions which is known as ligands. A typical coordination complex is bound to several donor atoms, which can either be the same or different. Coordination refers to the coordinate covalent bonds (dipolar bonds) between the ligands and the central atom.