Practice: Solubility of Sn(OH)2 was found to be 1.11 x 10-9 M; calculate Ksp of this compound.
Solubility is the maximum amount of solid dissolved in a solvent. Ksp measures the solubilities of solid ionic compounds in a solvent at equilibrium.
Ksp
Concept #1: Solubility Product Constant (Ksp)
Generally, the larger the Ksp, the more soluble the solid is.
Example #1: Given the following ionic compounds, which will have the highest [OH-] concentration? Hint: which is most soluble in water?
a) Fe(OH)2 Ksp = 4.87 x 10-17 b) Pb(OH)2 Ksp = 1.43 x 10-20
c) Mg(OH)2 Ksp = 2.06 x 10-13 d) Sn(OH)2 Ksp = 5.45 x 10-27
Concept #2: Ksp Calculations
Example #2: PbF2 is a white solid and has diverse applications in pharmaceuticals, metallurgy, and technology. If the concentration of lead (II) fluoride is 4.2 M with a Ksp = 3.6 x 10-8, calculate the molar solubility of this solid at 25ºC.
Practice: If a saturated solution of Ag2CO3 contains 2.56 × 10−4 M of Ag+ ions, determine its solubility product constant.
Practice: What is the solubility of CN− ions in a solution of 5.5 M Hg2(CN)2, with a Ksp of 5.0 × 10−40?
