Ksp SOLUBILITY EQUILIBRIUM

What is Ksp? Solubility product constant, last point of solubility Generally used for solutions which would be identified as forming a precipitate Ion-product expression: SrF2 (s) ↔ Sr +2 (aq) + 2 F - (aq) K sp = [Sr +2 ][F - ] 2

Write the ion-product expression for each of the following: a) magnesium carbonate b) iron (II) hydroxide C) calcium phosphate

Table 19.2 Solubility-Product Constants (K sp ) of Selected Ionic Compounds at 25 0 C Name, FormulaK sp Aluminum hydroxide, Al(OH) 3 Cobalt( II ) carbonate, CoCO 3 Iron( II ) hydroxide, Fe(OH) 2 Lead( II ) fluoride, PbF 2 Lead( II ) sulfate, PbSO 4 Silver sulfide, Ag 2 S Zinc iodate, Zn( I O 3 ) 2 3x x x x x x x Mercury( I ) iodide, Hg 2 I 2 3.9x10 -6

Example 1 Calcium oxalate has a measured solubility of 4.8 x M. Calculate K sp value. Write equation & K sp expression. Use ICE box format, plugin to expression & solve.

Example 2: Same set up, use unknown to solve for solubility. Calculate solubility of silver phosphate if K sp is 1.8 x

Example 3: Hint: Change solubility to Molarity first! Lead (II) sulfate is a key component in lead-acid batteries. Its solubility in water at 25˚C is 4.25 x g/100 mL solution. What is Ksp of PbSO 4 ?

Which is most soluble? Least soluble? No. of IonsFormulaCation/AnionK sp Solubility (M) 2MgCO 3 1/13.5x x PbSO 4 1/11.6x x BaCrO 4 1/12.1x x Ca(OH) 2 1/26.5x x BaF 2 1/21.5x x CaF 2 1/23.2x x Ag 2 CrO 4 2/12.6x x10 -5