The formula of tetraammineaquachlorocobalt(III) chloride is :

Options

A. `[Co(NH_(2))_(4)(H_(2)O)Cl]Cl_(2)`
B. `[Co(NH_(2))_(4)(H_(2)O)Cl]Cl`
C. `[Co(NH_(3))_(4)(H_(2)O)Cl]Cl_(2)`
D. `[Co(NH_(3))_(4)(OH)Cl_(2)]Cl`

Answer

To derive the formula of tetraammineaquachlorocobalt(III) chloride, we will follow these steps:

### Step 1: Identify the central metal ion and its oxidation state
The name "cobalt(III)" indicates that cobalt is the central metal ion and it has an oxidation state of +3.

**Hint:** Look for the oxidation state in the name; it is usually indicated in Roman numerals.

### Step 2: Identify the ligands
The term "tetraammine" indicates that there are four ammonia (NH₃) ligands. "Aqua" indicates the presence of one water (H₂O) molecule, and "chloro" indicates the presence of chloride ions (Cl⁻).

**Hint:** Ligands are usually mentioned before the central metal in the IUPAC name.

### Step 3: Determine the overall charge of the complex
- The cobalt ion has a charge of +3.
- Each ammonia (NH₃) is a neutral ligand (0 charge).
- The water molecule (H₂O) is also neutral (0 charge).
- Each chloride ion (Cl⁻) has a charge of -1.

To balance the charges:
- The total positive charge from cobalt is +3.
- The total negative charge from two chloride ions (since we need two to balance the overall charge) is -2.

Thus, the overall charge of the complex is:
\[ +3 + 0 + 0 - 2 = +1 \]

**Hint:** Always check the total charge to ensure it balances out.

### Step 4: Write the formula
Based on the information gathered:
- We have 4 ammonia ligands: NH₃₄
- We have 1 water molecule: H₂O
- We have 2 chloride ions: Cl₂

Putting it all together, the formula for the coordination compound is:
\[ \text{[Co(NH}_3\text{)}_4\text{(H}_2\text{O)(Cl)}_2] \]

### Step 5: Write the final formula
Since the complex is cobalt(III) chloride, we denote it as:
\[ \text{[Co(NH}_3\text{)}_4\text{(H}_2\text{O)(Cl)}_2] \cdot 2\text{Cl} \]

Thus, the final formula is:
\[ \text{[Co(NH}_3\text{)}_4\text{(H}_2\text{O)(Cl)}_2] \]

### Final Answer
The formula of tetraammineaquachlorocobalt(III) chloride is:
\[ \text{[Co(NH}_3\text{)}_4\text{(H}_2\text{O)(Cl)}_2] \cdot 2\text{Cl} \]

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