The `IUPAC` name of `[CO(NH_(2))_(6)]CI_(3)` is______ .

Explanation

To determine the IUPAC name of the complex `[Co(NH₂)₆]Cl₃`, we will follow a systematic approach:

### Step 1: Identify the Ligands
The complex contains six amine ligands, which are represented by `NH₂`. In coordination chemistry, amine ligands are referred to as "ammine".

**Hint:** Ligands are named first in the IUPAC naming convention, and their prefixes indicate the number of ligands present.

### Step 2: Count the Number of Ligands
Since there are six ammine ligands, we use the prefix "hexa-" to denote this quantity.

**Hint:** Remember to use the appropriate Greek prefixes for the number of ligands.

### Step 3: Name the Central Metal Atom
The central metal atom in this complex is cobalt, which is represented by "Co".

**Hint:** The name of the metal is included after the ligands in the name.

### Step 4: Determine the Oxidation State of the Metal
To find the oxidation state of cobalt, we set up the equation based on the overall charge of the complex. The ammine ligands are neutral (0 charge), and there are three chloride ions (Cl⁻) which each have a charge of -1.

Let the oxidation state of cobalt be \( x \):
\[ x + 0 - 3 = 0 \]
Thus, \( x = +3 \).

**Hint:** The oxidation state is crucial for the correct naming of the complex and is indicated in Roman numerals.

### Step 5: Combine the Names
Now we can combine the names of the ligands and the metal with its oxidation state. The name will be:
- Ligands: "hexaammine"
- Metal: "cobalt"
- Oxidation state: "(III)"
- Counter ion: "chloride"

So, the full name of the complex is **"hexammine cobalt(III) chloride"**.

### Final Answer
The IUPAC name of `[Co(NH₂)₆]Cl₃` is **hexammine cobalt(III) chloride**.

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