Question

The IUPAC name of $K_2\left[Ni\right(CN{)}_4]$ and$K_2\left[Ni\right(Cl{)}_4]$ are :

• A. potassium tetracyanonickelate(II), potassium tetrachloronickelate(II)
• B. tetracyanopotassiumnickelate(II), tetrachloropotassiumnickelate(II)
• C. tetracyanonickel(II), tetrachloronickel(II)
• D. potassium tetracyanonickel(II), potassiumtetrachloronickel(II)

Answer 1

The correct option is A potassium tetracyanonickelate(II), potassium tetrachloronickelate(II)

IUPAC naming of coordination compound:

The names of coordination compounds are derived by the following principles of nomenclature,
1. The cation is named first in both positively and negatively charged coordination entities.
2. The ligands are named in an alphabetical order before the name of the central atom/ion.

Also, the number of cations or anions is not denoted in the name of a coordination compound. So, in this case the counter ion is named as potassium and not dipotassium.

The oxidation number of Ni in both the compounds is $x-4=-2\to =2$
$K_2\left[Ni\right(CN\left)4\right]-$ potassium tetracyanonickelate(II)
$K_2\left[Ni\right(Cl\left)4\right]-$ potassiumtetrachlornickelate(II)