In the complex `[Co(NH_3)_(6)][CdCl_x]` the oxidation number of cobalt is +3 . The value of x is

Options

A. 3
B. 4
C. 2
D. 5

Answer

To solve the problem, we need to determine the value of \( x \) in the complex \([Co(NH_3)_6][CdCl_x]\) given that the oxidation number of cobalt (Co) is +3.

### Step-by-Step Solution:

1. **Identify the oxidation states:**
- The oxidation state of cobalt (Co) is given as +3.
- Ammonia (NH₃) is a neutral ligand, which means it has an oxidation state of 0.
- Cadmium (Cd) is in Group 12 of the periodic table and typically has an oxidation state of +2.
- Chloride (Cl) has an oxidation state of -1.

2. **Set up the equation for the overall charge:**
- The overall charge of the complex ion \([Co(NH_3)_6]^{3+}\) is +3 (due to Co).
- The charge of the cadmium complex \([CdCl_x]\) must balance the charge from the cobalt complex to make the entire compound neutral.

3. **Write the expression for the charge balance:**
- The charge contributed by the cadmium ion is +2.
- The charge contributed by \( x \) chloride ions is \( -1 \times x \).
- Therefore, the total charge from the cadmium complex is \( +2 - x \).

4. **Set the total charge to zero:**
- Since the overall complex must be neutral, we can write the equation:
\[ +3 + (2 - x) = 0 \]

5. **Solve for \( x \):**
- Rearranging the equation gives:
\[ 3 + 2 - x = 0 \]
\[ 5 - x = 0 \]
\[ x = 5 \]

6. **Conclusion:**
- The value of \( x \) is 5.

### Final Answer:
The value of \( x \) is 5.