Silver Chromate Ksp

Silver chromate is a sparingly soluble salt with the chemical formula Ag2CrO4. When this salt is placed in water, it dissociates into its constituent ions according to the following equation:

Ag2CrO4(s) ⇌ 2Ag+(aq) + CrO42-(aq)

The equilibrium constant for this reaction is known as the solubility product constant, or Ksp. The value of Ksp for silver chromate is determined by measuring the concentrations of the dissolved ions at equilibrium and applying the law of mass action.

Ksp = [Ag+]^2[CrO42-]

The square brackets denote the concentrations of the ions in solution. Because silver chromate is only sparingly soluble, most of the solid remains undissolved and the concentrations of the ions are very low. Therefore, Ksp has a relatively small value. For silver chromate, the experimental value of Ksp is approximately 1.1 x 10^-12.

This value indicates that silver chromate is highly insoluble in water, as only a very small amount of it will dissolve to form ions. It also means that if enough silver and chromate ions are present in a solution, they will combine to form solid silver chromate until the concentrations of the ions are in equilibrium with the solid. This property can be used to selectively precipitate silver ions from a solution containing other metal ions, as silver chromate will form a distinctive yellow precipitate.