Select the correct `IUPA` name for `[CoCI_(2)(en)_(2)]_(2)(CIO_(3))_(2)` .

Options

A. Dichloridobis (ethylenediamine)cobalt(III)chlorate .
B. Dichloridobis (ethane-1,2-diamine)cobalt(III)chlorate .
C. bis{dichloridoethylenediaminecobalt(III)}chlorate
D. bis{di(chlorido)ethylenediaminecobalt(III)}chlorate

Answer

To determine the correct IUPAC name for the coordination compound \([CoCl_2(en)_2](ClO_3)_2\), we will follow these steps:

### Step 1: Identify the Components
The coordination compound consists of:
- Cobalt (Co) as the central metal atom.
- Two chloride ions (Cl) as ligands.
- Two ethylenediamine (en) ligands.
- Two chlorate ions (ClO3) as counter ions.

### Step 2: Name the Ligands
1. **Chloride Ligand**: The ligand derived from chloride is called "chlorido".
2. **Ethylenediamine Ligand**: Ethylenediamine is a bidentate ligand and is simply referred to as "ethylenediamine" or can also be called "ethane-1,2-diamine".

### Step 3: Determine the Oxidation State of Cobalt
To find the oxidation state of cobalt (Co), we can set up the following equation:
- Let the oxidation state of cobalt be \(x\).
- The total charge from the two chloride ligands is \(-2\) (since each chloride is \(-1\)).
- The ethylenediamine ligands are neutral, contributing \(0\).
- The overall charge of the complex ion is \(+1\) (since it is paired with two \(-1\) chlorate ions, giving a total of \(-2\) charge).

Thus, we can write the equation:
\[ x - 2 = +1 \]
Solving for \(x\):
\[ x = +3 \]

### Step 4: Arrange the Ligands in Alphabetical Order
When naming the ligands in the IUPAC name, we arrange them in alphabetical order based on the ligand names:
- "Chlorido" comes before "ethylenediamine".

### Step 5: Use Appropriate Prefixes
Since we have:
- Two chlorido ligands: we use the prefix "di" → "dichlorido".
- Two ethylenediamine ligands: we use the prefix "bis" → "bis(ethylenediamine)".

### Step 6: Combine the Components
Now we can put all the components together:
- Ligands: "dichlorido" and "bis(ethylenediamine)"
- Central metal: "cobalt"
- Oxidation state: \(+3\) → written as "cobalt(III)"
- Anionic part: "chlorate" → since it is a counter ion, it will be mentioned at the end.

### Final IUPAC Name
The complete IUPAC name for the compound \([CoCl_2(en)_2](ClO_3)_2\) is:
**dichlorido bis(ethylenediamine) cobalt(III) chlorate**.

### Summary of Steps
1. Identify the components of the coordination compound.
2. Name the ligands.
3. Determine the oxidation state of the central metal.
4. Arrange the ligands in alphabetical order.
5. Use appropriate prefixes for the number of ligands.
6. Combine all components to form the full name.