Question

According to IUPAC nomenclature, sodium nitroprusside is named as:
A)Sodium pentacyanonitrosyl ferrate(III)
B)Sodium nitroferricyanide
C)Sodium nitroferricyanide
D)Sodium pentacyanonitrosyl ferrate(II)

Answer 1

Hint: As the coordination compounds or complexes can be sufficiently complicated, a few formal rules were suggested by the IUPAC to name these compounds. Nomenclature is important because of the need to have an unambiguous method of describing formulas.

Complete step-by-step answer:
The general rules are as below:
Rule 1: Order of naming ions. The cation is named at first in both positively and negatively charged coordination entities followed by the name of negative ions. If the compound is ionic, the name of the cation is mentioned first followed by the name of anion. For the non-ionic complexes, the name of the whole complex is written at once in one word.
Rule 2:Naming of coordination entity. In naming the coordination entity, the names of the ligands are written first followed by the name of the central ion. The oxidation number of the central metal atom is expressed by Roman Numeral in parentheses just after the name of the central atom.
Rule 3:Naming of ligands. The central metal ion in a complex is surrounded by positive or negative or neutral ligands. The names of anionic ligands are modified to the end in ‘O’. The names of cationic ligands are modified to the end as ‘ium’.
Rule 4:Order of naming ligands. According, to the latest IUPAC conventions, the names of the ligands in the complex surrounding the central metal atom are written in alphabetic order of preference irrespective of whether they are negative or neutral.
Sodium nitroprusside is $\mathrm{Na}_{2}\left[\mathrm{Fe}(\mathrm{CN})_{5} \mathrm{NO}\right]$
Now according to the nomenclature discussed, we have
Here, as you can see that this is a coordination compound.
\left[\mathrm{Fe}(\mathrm{CN})_{5} \mathrm{NO}\right] is anionic sphere here. Cyanide ion is the ligand and also the NO is the ligand.
Sodium pentacyanonitrosyl ferrate (III).

The answer is A.

Note: Always add the -ium and -o according to the nature of the ligands. Find out the correct oxidation state of the central metal atom.