How many ions are produced from the complex $[Co(NH_{3})_{6}]Cl_{2}$ in solution ?

Question

Accepted Answer

The complex $[Co(NH_{3})_{6}]Cl_{2}$ is a coordination compound consisting of a cobalt ion surrounded by six ammonia (NH₃) ligands, with two chloride ions (Cl⁻) outside the coordination sphere. When this complex is dissolved in water, it dissociates into ions.

1. **Explanation for Option 3 (Correct Answer):**
   - The complex $[Co(NH_{3})_{6}]Cl_{2}$ dissociates in solution as follows:
     $$
     [Co(NH_{3})_{6}]Cl_{2} \rightarrow [Co(NH_{3})_{6}]^{2+} + 2Cl^{-}
     $$
   - In this dissociation, one complex ion $[Co(NH_{3})_{6}]^{2+}$ and two chloride ions (Cl⁻) are produced.
   - Therefore, the total number of ions produced is 1 (from the complex ion) + 2 (from the chloride ions) = 3 ions.
   - This supports Option 3 as the correct answer.

2. **Explanation for why other options are incorrect:**
   - **Option 1 (9 ions):** This option is incorrect because the dissociation of $[Co(NH_{3})_{6}]Cl_{2}$ only produces 3 ions, not 9. The number 9 might be mistakenly considered if one assumes each ammonia ligand dissociates separately, which is not the case here.
   - **Option 2 (8 ions):** This option is incorrect because, similar to Option 1, it overestimates the number of ions produced. The complex produces only 3 ions upon dissociation.
   - **Option 4 (2 ions):** This option is incorrect because it underestimates the number of ions. It might consider only the chloride ions, ignoring the complex ion $[Co(NH_{3})_{6}]^{2+}$, which is also an ion in solution.

In conclusion, the correct number of ions produced from the dissociation of $[Co(NH_{3})_{6}]Cl_{2}$ in solution is 3, making Option 3 the correct choice.