The formula of the complex triamminetri(nitrito-O) Cobalt (III) is

Options

A. `[Co(ONO)_(3)(NH_(3))_(3)]`
B. `[Co(NO_(2))_(3)(NH_(3))_(3)]`
C. `[Co(ONO_(2))_(3)(NH_(3))_(3)]`
D. `[Co(NO_(2))(NH_(3))_(3)]`

Explanation

To find the formula of the complex triamminetri(nitrito-O) cobalt(III), we can follow these steps:

### Step 1: Identify the central metal ion and its oxidation state.
- The central metal ion in this complex is cobalt (Co), and the oxidation state is +3 (indicated by the Roman numeral III).

**Hint:** Look for the Roman numeral in the name of the complex to determine the oxidation state of the metal.

### Step 2: Identify the ligands and their quantities.
- The name "triamine" indicates that there are three amine ligands (NH3).
- The name "tri(nitrito-O)" indicates that there are three nitrito ligands, specifically bonded through the oxygen atom (ONO).

**Hint:** The prefix "tri-" before a ligand name indicates the number of that type of ligand present in the complex.

### Step 3: Write the formula for each ligand.
- The formula for the amine ligand is NH3.
- The formula for the nitrito-O ligand is NO2, but since it is bonded through oxygen, we write it as ONO.

**Hint:** Remember that ligands can have different bonding sites; in this case, nitrito-O means it bonds through the oxygen atom.

### Step 4: Combine the ligands with the central metal ion.
- The overall formula will include the central metal ion (Co) with its oxidation state, followed by the ligands.
- Since there are three NH3 ligands and three ONO ligands, we can express this as:
- 3 NH3 for triamine
- 3 ONO for tri(nitrito-O)

### Step 5: Write the complete formula.
- The complete formula for the complex is:
\[ \text{[Co(NH}_3\text{)}_3(\text{ONO})_3]^{3+} \]

**Hint:** The charge of the complex can often be determined by considering the charges of the ligands and the oxidation state of the metal.

### Final Formula:
Thus, the formula of the complex triamminetri(nitrito-O) cobalt(III) is:
\[ \text{[Co(NH}_3\text{)}_3(\text{ONO})_3]^{3+} \]

### Summary of Steps:
1. Identify the central metal and its oxidation state.
2. Identify the ligands and their quantities.
3. Write the formula for each ligand.
4. Combine the ligands with the central metal ion.
5. Write the complete formula.