IUPAC name of sodium cobaltinitrite is

Options

A. Sodium cobaltinitrite
B. Sodium hexanitritocobaltate (III)
C. Sodium hexanitrocobalt (III)
D. Sodium hexanitritocobaltate (II)

Explanation

To determine the IUPAC name of sodium cobaltinitrite, we can follow these steps:

### Step 1: Identify the components of the compound
- Sodium (Na) is a cation.
- Cobalt (Co) is the central metal atom.
- The ligand is nitrite (NO2^-), which is a bidentate ligand in this case.

### Step 2: Determine the oxidation state of cobalt
- The nitrite ion (NO2^-) has a charge of -1.
- Since there are three nitrite ions in the compound, the total negative charge contributed by the ligands is -3.
- To balance this charge, cobalt must have an oxidation state of +3.

### Step 3: Naming the ligands
- The nitrite ion is named as "nitrito" when it acts as a ligand.
- Since there are three nitrito ligands, we use the prefix "tri" to indicate the number of ligands.

### Step 4: Naming the central metal
- Since cobalt is in the +3 oxidation state, we name it "cobalt(III)".
- However, because cobalt is part of an anionic complex, we change the name to "cobaltate".

### Step 5: Combine the names
- The full name of the compound is constructed by combining the names of the ligands and the central metal.
- The cation (sodium) is named first, followed by the name of the anionic complex.

### Final IUPAC Name
The IUPAC name of sodium cobaltinitrite is **sodium nitrito cobaltate(III)**.

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