The IUPAC name of the complex `[Co(NH_3)_4(H_2O)Cl]Cl_2` is

Explanation

To determine the IUPAC name of the complex \([Co(NH_3)_4(H_2O)Cl]Cl_2\), we will follow these steps:

### Step 1: Identify the central metal ion and its oxidation state
The central metal ion in the complex is cobalt (Co). To find its oxidation state, we can set up the following equation based on the charges of the ligands and the overall charge of the complex.

- Let the oxidation state of cobalt be \(x\).
- The ligands are:
- 4 ammonia (\(NH_3\)), which are neutral (0 charge).
- 1 water (\(H_2O\)), which is also neutral (0 charge).
- 1 chloride (\(Cl\)), which has a charge of -1.
- The overall charge of the complex is neutral (0).

The equation can be set up as:
\[ x + 0 + 0 - 1 = 0 \]
This simplifies to:
\[ x - 1 = 0 \]
Thus, \(x = +1\).

However, since the complex is associated with 2 chloride ions outside the coordination sphere, we need to consider their contribution to the overall charge. The two chloride ions contribute a total charge of -2. Therefore, the equation should be:
\[ x - 1 - 2 = 0 \]
This simplifies to:
\[ x - 3 = 0 \]
Thus, \(x = +3\).

### Step 2: Name the ligands
The ligands in the complex are:
- 4 ammonia molecules, which are named "tetraamine" (since "amino" is replaced by "amine" for neutral ligands).
- 1 water molecule, which is named "aqua".
- 1 chloride ion, which is named "chlorido".

### Step 3: Combine the names of the ligands
According to IUPAC nomenclature, we list the ligands in alphabetical order, ignoring any prefixes that indicate the number of each ligand. Therefore, we will list "aqua" first, followed by "tetraamine" and then "chlorido".

### Step 4: Name the central metal ion with its oxidation state
The central metal ion is cobalt, and we have determined its oxidation state to be +3. In the name, we denote this as "cobalt(III)".

### Step 5: Combine everything to form the complete name
Putting it all together, we have:
- Ligands: "tetraamine", "aqua", "chlorido"
- Central metal: "cobalt(III)"
- The two chloride ions outside the coordination sphere indicate that we should add "dichloride" at the end.

Thus, the complete IUPAC name of the complex \([Co(NH_3)_4(H_2O)Cl]Cl_2\) is:
**Tetraammineaquachloridocobalt(III) dichloride.**

### Summary of the IUPAC Name
The IUPAC name is: **Tetraammineaquachloridocobalt(III) dichloride.**

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