Question

The IUPAC name for $[Ni{(N{H_3})_4}][NiC{l_4}]$ is :
A. Tetrachloridonickel(II)-tetraamminenickel(II)
B. Tetraamminenickel(II)-tetrachloridonickel(II)
C. Tetraamminenickel(II)-tetrachloronickelate(II)
D. Tetrachloridonickel(II)-tetraamminenickelate(II)

Answer 1

Hint:Firstly, separate the cationic and the anionic part. Then the students need to find the charge on nickel by calculating the oxidation states of other compounds. In this question, $[Ni{(N{H_3})_4}]$ is the cationic part and $[NiC{l_4}]$ is the anionic part..


Complete solution:
As we know the oxidation number of ammonia is neutral (0) and the oxidation number of chlorine is -1.
Let us consider, the oxidation state of nickel is x in $[Ni{(N{H_3})_4}]$ so
$
2x + 4( - 1) = 0 \\
\Rightarrow 2x = 4 \\
\Rightarrow x = 2 \\
 $
 $
2x + 0 + 4( - 1) = 0 \\
\Rightarrow 2x = 4 \\
\Rightarrow x = 2 \\
$
Similarly, in ​ $[NiC{l_4}]$,
$
2x + 4( - 1) = 0 \\
\Rightarrow 2x = 4 \\
\Rightarrow x = 2 \\
$
So, we get the oxidation state of Ni ​] is 2.
So, The I.U.P.A.C name for $[Ni{(N{H_3})_4}][NiC{l_4}]$ is tetraamminenickel(II)-tetrachloronickelate(II)

Therefore,the correct option is (C).


Additional information:The oxidation state of Ni is written in parenthesis in roman numerals. Roman in the naming represent the oxidation state of the central metal atom. In the naming ‘ate’ is used in the end of nickel because in the anionic part the metal nickel is present. Also, while naming the coordination compounds, students should keep in mind that the name of the complex cation is written first followed by the name of the complex anion. Here, complex cation contains four amine ligands and complex anion contains 4 chloride ligands.
A coordination compound is defined as a compound which contains coordinate bonds, basically between a central metal atom with other atoms and groups. Important roles of coordination are as industrial catalysts in controlling reactivity, and also useful in biochemical processes.


Note:Students usually forget the oxidation number of the elements, so it is advisable to learn the oxidation numbers thoroughly, then proceed to the question. Also, students should distinguish the cationic and anionic part very properly, otherwise the whole nomenclature will be wrong. Students should also concentrate while ticking the correct answer because all the options are very similar to each other.