IUPAC name of `|Co(ONO)(NH_(3))_(5)Cl_(2)|` is

Options

A. pentamminenitrocobalt(II)chloride
B. pentamminenitrosocobalt(III)chloride
C. pentamminenitritocobalt(III)chloride
D. pentammineoxo-nitrocobalt(III)chloride

Answer

To determine the IUPAC name of the coordination compound \[Co(ONO)(NH_3)_5Cl_2\], we will follow these steps:

### Step 1: Identify the central metal atom
The central metal atom in the complex is cobalt (Co).

### Step 2: Identify the ligands
The ligands present in the complex are:
- 5 ammonia (NH₃) molecules, which are neutral ligands.
- 1 nitrito ligand (ONO), which is a bidentate ligand.
- 2 chloride (Cl) ions, which are anionic ligands.

### Step 3: Determine the oxidation state of the central metal
To find the oxidation state of cobalt, we can use the following formula:
\[ \text{Oxidation state of Co} + \text{(number of Cl)} \times (-1) + \text{(number of NH}_3) \times (0) + \text{(number of ONO)} \times (-1) = 0 \]

Let the oxidation state of cobalt be \( x \):
\[ x + 2(-1) + 0 + (-1) = 0 \]
\[ x - 2 - 1 = 0 \]
\[ x - 3 = 0 \]
\[ x = +3 \]

Thus, the oxidation state of cobalt is +3.

### Step 4: Name the ligands
- The ammonia ligands are named as "ammine".
- The nitrito ligand (ONO) is named as "nitrito".
- The chloride ligands are named as "chloro".

### Step 5: Arrange the ligands in alphabetical order
When naming the ligands, we arrange them in alphabetical order, regardless of their prefixes (di-, tri-, etc.):
- "ammine" (A)
- "chloro" (C)
- "nitrito" (N)

Thus, the order will be:
- 5 ammine
- 2 chloro
- 1 nitrito

### Step 6: Combine the names and include the oxidation state
The complete name will be:
- The ligands: "pentaammine", "nitrito", and "dichloro".
- The central metal with its oxidation state: "cobalt(III)".

Putting it all together, we get:
**IUPAC Name: pentaammine nitrito cobalt(III) dichloride**

### Final Answer:
**The IUPAC name of \[Co(ONO)(NH_3)_5Cl_2\] is pentaammine nitrito cobalt(III) dichloride.**

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