Question

Is Ag₂S more soluble in 0.1 M NH3 solution than distilled water? Explain briefly

Answer 1

Is Ag₂S more soluble in 0.1 M NH3 solution than distilled water? Explain briefly

the molar solubility of Ag2S ; Ksp = 6.2 *10^(-51)

Ag2S is insoluble in water.

The following equilibium exists when Ag2S is added in to water:
Ag2S (s) <--> 2Ag+(aq) + S^2-(aq) --(1)

due to insolubility of Ag2S, the equilibrium lies to the left.

In aq NH3, : ammonia; NH3 acts as a ligand and forms a complex with the silver ion; Ag+ as follows:

Ag+(aq) + 2NH3(aq) <-->[Ag(NH3)2]+ (aq) --(2)

Reaction(2) lowers the concentration of Ag+ due to formation of complex; [Ag(NH3)2]+ as the result of this Ag2S (s) will soluble more and shifts the equilibrium of (1) to the left side.