Question

The IUPAC name of ${{K}_{3}}[Fe{{(CN)}_{6}}]$ is:
A. potassium hexacyanoferrate(II)
B. potassium hexacyanoferrate(III)
C. potassium hexacyanoiron(II)
D. tripotassium hexacyanoiron(II)

Answer 1

Hint: IUPAC gives us some rules for the naming of organic compounds which can also be referred to as nomenclature of organic compounds. IUPAC stands for International Union of Pure and Applied Chemistry.

Complete answer: IUPAC nomenclature gives us information on writing the name of chemical compounds. There are some general rules for it. To write the name of this compound we have to follow some rules.
a. Metal/non-metal present outside the bracket is named first and name remains the same as it is known in periodic table here the compound having potassium so the name is started with potassium.
b. After naming the metal/non-metal outside the bracket we have to give name to the ligand first and number of ligands is used as suffix like if two ligands are present then it is represented as di, 3 as tri, 4-tetra, 5-penta and 6 as hexa now in the given compound 6 atoms of CN ligands are present which can be named as hexacyano.
c. After that name the metal ion present with the ligands here iron is present which is a coordination complex that is written as ferrate. Hence the name is potassium hexacyanoferrate.
d. Last step is to calculate the oxidation number of the element in this compound oxidation state of Fe is calculated as:
$x+(-1)6=-3$; $x=-3+6=3$i.e. +3 and it is written in roman manner in the last name.

Hence the IUPAC name of the given compound is potassium hexacyanoferrate(III) i.e. option B is the correct answer.

Note: Potassium Hexacyanoferrate (III) is commonly known by the name potassium ferricyanide which is a chemical compound. It is a bright red salt that is soluble in water and its solution exhibits green-yellow fluorescence. It can be manufactured by passing chlorine through a solution of potassium ferrocyanide.