IUPAC name of ` K_(3)[Fe(C_(2)O_(4))_(3)]` is

Options

A. potassium trioxalatoferrate (I)
B. potassium tetraoxalatoferrate (III)
C. Potassium trioxalatoferrate (III)
D. Potassium trioxalatoferrate (II)

Answer

To determine the IUPAC name of the complex compound \( K_3[Fe(C_2O_4)_3] \), we will follow the steps of nomenclature for coordination compounds.

### Step-by-Step Solution:

1. **Identify the Cation and Anion**:
- The cation in this compound is potassium \( K^+ \).
- The anion is the complex ion \( [Fe(C_2O_4)_3]^{3-} \).

2. **Determine the Ligand**:
- The ligand present is oxalate, which is derived from oxalic acid and has the formula \( C_2O_4^{2-} \).
- Since there are three oxalate ligands, we denote this as "tri-oxalato".

3. **Determine the Central Metal and its Oxidation State**:
- The central metal atom is iron \( Fe \).
- To find the oxidation state of iron, we set up the equation based on the charge balance:
- Let the oxidation state of iron be \( x \).
- The total charge from three oxalate ligands is \( 3 \times (-2) = -6 \).
- The overall charge of the complex ion is \( -3 \) (since it is \( [Fe(C_2O_4)_3]^{3-} \)).
- Therefore, we have:
\[ x - 6 = -3 \implies x = +3 \]
- Thus, the oxidation state of iron is \( +3 \).

4. **Construct the Name**:
- According to IUPAC nomenclature, the name starts with the cation followed by the anion.
- The cation is potassium, and we write it first.
- The ligand is tri-oxalato, and since the central metal is iron with an oxidation state of \( +3 \), we use the suffix "ferrate" to indicate the iron in the anionic complex.
- Finally, we include the oxidation state in Roman numerals in parentheses.

5. **Final Name**:
- The complete IUPAC name is:
\[ \text{Potassium tri-oxalato ferrate(III)} \]