Question

Give the name of the complex compound ${K_3}\left[ {Fe{{\left( {{C_2}{O_4}} \right)}_3}} \right]$ according to IUPAC system:
A.Potassium Ferric oxalate
B.Potassium tris oxalato iron (III)
C.Potassium trioxalatoferrate (III)
D.Tripotassium trioxalatoferrate (III)

Answer 1

We can define the coordination complex as a compound that consists of a central atom (ion) that is metallic and is called the coordination centre. It is surrounded by array bound molecules (or) ions called as ligands (or) complexing agents. Transition metals are coordination complexes. A coordination complex whose centre has a metal atom is known as a metal complex of d block element.

Complete step by step answer:
We can define complex structures as compounds that are made of a central metal ion bounded by molecules or ions known as ligands. These ligands are involved in the central metal ion by means of coordinate covalent bonds. The central metal ion contains a positive charge. The ligands are rich with unshared pairs of electrons. These electrons are donated to the metal ion in order to reduce the positive charge on the metal ion. This kind of bonding is called a coordinate bond.
Rules for naming the complex:
The ligands are named first, succeeded by the name of the metal atom or ion. A Roman numeral in parentheses signifies the oxidation number of the central metal ion.
Neutral ligands, such as ${H_2}NC{H_2}C{H_2}N{H_2}$ (ethylenediamine) contain the same name as the molecule, other than ${H_2}O$ (aqua),$N{H_3}$ (ammine), $CO$ (carbonyl), and $NO$ (nitrosyl).
Anionic ligands end in -o; for anions which end in -ide (like chloride), -ate (like sulfate), and -ite (like nitrite), alter the endings as -ide, -ido, ate, -ato, -ite, -ito.
${C_2}{O_4}$ is the oxalate ligand.
If the complex ion is an anion, we have to descend the metal atom name, and put suffix –ate. Iron is a negative ion in the given compound, therefore the name will be ferrate.
In the given compound ${K_3}\left[ {Fe{{\left( {{C_2}{O_4}} \right)}_3}} \right]$, the charge on potassium atom is +1, as we can see three potassium atoms. So, the overall charge is +3.
The overall charge on $Fe{\left( {{C_2}{O_4}} \right)_3}$ is -3. The oxalate group has a charge of -2. The oxidation state on iron is +3. Therefore, the IUPAC name of the complex is $Fe{\left( {{C_2}{O_4}} \right)_3}$ is potassium trioxalatoferrate (III).
Therefore, the option (C) is correct.

Note:
The complex potassium trioxalatoferrate (III) is often seen in its trihydrate form. It appears in lime green and is otherwise known as potassium trioxalatoferrate (or) potassium tris (oxalate) ferrate (III). We can use this compound in photometry and actinometry, blueprints etc.