Chemistry 115 Chapter 17. Solubility and Simultaneous Equilibria

Specific Objectives. The student should be able to:

1. Write the solubility product expression, Ksp for a slightly soluble compound.
2. Calculate Ksp from the solubility of an ionic compound or solubility from the value of Ksp.
3. Calculate the effect of common ions on the aqueous solubilities of sparingly soluble salts.
4. Describe how the presence of "uncommon" ions in solution or the formation of ion pairs in concentrated solutions increases the solubility of a sparingly soluble salt.
5. Determine if a salt will precipitate from solution based on the concentrations of its ions.
6. Determine the concentration of ions remaining in solution after precipitation and predict whether precipitation will be complete.
7. Explain how fractional precipitation works and when it can be used.
8. Describe, through net ionic equations and calculations, the effect of pH on the precipitation and dissolving of impacted compounds.
9. Write equations showing the effect of complex ion formation on other equlibrium processes such as solubility equilibria.
10. Use complex ion formation constants, K_f (from Appendix E-6 in the text), to compute the concentrations in solution of: free ions, ligands, and complex ions.
11. Use K_f values along with Ksp values to determine the solubilities of slightly soluble solutes in the presence of complexing ligands.
12. Calculate the solubilities of certain solutes in the poresence of complexing ligands.
13. Predict whether metal sulfides will precipitate from saturated H₂S(aq) solutions of known pH