The oxidation number of `Co ` in ` [Co(NH_(3))_(3)(NO_(2))_(3)]` is

Options

A. `+3`
B. `0`
C. `-3`
D. `6`

Explanation

To find the oxidation number of cobalt (Co) in the complex ion \([Co(NH_3)_3(NO_2)_3]\), we can follow these steps:

### Step 1: Identify the ligands and their charges
- The complex contains three ammonia (\(NH_3\)) ligands. Ammonia is a neutral ligand, so it contributes 0 to the overall charge.
- The complex also contains three nitrito (\(NO_2\)) ligands. The nitrito ligand can be considered as having a charge of -1.

### Step 2: Set up the equation for the oxidation number
Let the oxidation number of cobalt be \(X\). The overall charge of the complex is neutral (0). Therefore, we can set up the equation based on the contributions of the ligands:

\[ X + (0 \times 3) + (-1 \times 3) = 0 \]

### Step 3: Simplify the equation
Substituting the values into the equation gives:

\[ X - 3 = 0 \]

### Step 4: Solve for \(X\)
Now, we can solve for \(X\):

\[ X = 3 \]

### Conclusion
The oxidation number of cobalt in \([Co(NH_3)_3(NO_2)_3]\) is +3.

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