How many charges are present in CoCl₃.3NH₃ compound?

Question

Question

This question was previously asked in

DSSSB PGT Chemistry (Female) Official Paper (Held On: 06 Jul, 2018 Shift 1)

Answer 1

CONCEPT:

Coordination Compounds and Ionization

Coordination compounds consist of a central metal ion surrounded by ligands.
Some ligands are inside the coordination sphere (in square brackets), while others are ionizable and contribute to the charge in solution.
The total number of ions in solution = charged species after dissociation.

EXPLANATION:

Given compound: CoCl₃·3NH₃
It is not a fully specified coordination complex, so we must infer its structure.
Co³⁺ typically forms 6-coordinate complexes. Here, only 3 NH₃ are coordinated, so the likely structure is:
[Co(NH₃)₃Cl₃] — all 3 Cl⁻ are inside the coordination sphere.
But in that case, the complex is neutral, i.e., no ionization occurs ⟶ 0 charge.
If even one Cl⁻ is outside the coordination sphere, it will ionize. But since the formula is CoCl₃·3NH₃, not [Co(NH₃)₆]Cl₃, it suggests that the complex is neutral and contains no free ions.

Therefore, the number of charges present in CoCl₃·3NH₃ is 0.