. One mole of the complex compound Co(NH3)5Cl3, gives 3 moles of ions on dissolution in water. One mole of the same complex reacts with two moles of AgNO3 solution to yield two moles of AgCl (s). The structure of the complex is

To understand the structure of the complex compound Co(NH3)5Cl3, we need to delve into its composition and behavior in solution. This cobalt complex is an example of a coordination compound, where cobalt (Co) is the central metal ion surrounded by ligands. In this case, the ligands are five ammonia (NH3) molecules and three chloride (Cl) ions.

Analyzing the Dissolution Process

When Co(NH3)5Cl3 dissolves in water, it dissociates into ions. The information provided states that one mole of this complex yields three moles of ions. This can be explained as follows:

• One mole of Co(NH3)5Cl3 dissociates into one cobalt ion (Co^3+) and three chloride ions (Cl^-).
• The ammonia ligands remain coordinated to the cobalt ion and do not dissociate into separate ions.

Thus, the total number of ions produced is:

• 1 Co^3+ ion
• 3 Cl^- ions

This gives us a total of 1 + 3 = 4 ions, which seems to contradict the initial statement of yielding 3 moles of ions. However, it’s important to note that the complex may exist in a specific equilibrium state in solution, which can affect the total count of observable ions.

Reaction with Silver Nitrate

The reaction of Co(NH3)5Cl3 with silver nitrate (AgNO3) is another crucial aspect of understanding its structure. The complex reacts with two moles of AgNO3 to produce two moles of AgCl (s). This indicates that the chloride ions are involved in the reaction:

• Each mole of AgNO3 provides one Ag^+ ion, which reacts with one Cl^- ion to form insoluble AgCl.
• Since two moles of AgNO3 yield two moles of AgCl, it suggests that two of the three chloride ions from the complex are released during this reaction.

Implications for the Structure

Given that two chloride ions are released in the reaction with AgNO3, it implies that one chloride ion remains coordinated to the cobalt ion in the complex. Therefore, the structure of Co(NH3)5Cl3 can be inferred to be:

• A cobalt ion at the center.
• Five ammonia molecules acting as neutral ligands.
• One chloride ion remaining as a ligand, while two chloride ions are free in solution.

Conclusion on the Structure

In summary, the structure of Co(NH3)5Cl3 can be represented as a cobalt ion surrounded by five ammonia ligands and one chloride ion, with two chloride ions dissociating into the solution. This coordination environment is typical for cobalt complexes, where the geometry is often octahedral due to the six ligands surrounding the central metal ion. Understanding these interactions and the behavior of the complex in solution provides valuable insights into its chemical properties and reactivity.