Session Overview
| Modules | Aqueous Solutions |
| Concepts | solute, solvent, solution, solubility rules, solubility product |
| Keywords | water, mixture, colloid, ionic compound, van der Waals force, Madelung constant, suspension, dispersion, molarity, crystallization, miscibility, precipitation, equilibrium constant, saturation, conductivity, common ion effect, homogenization, Arrhenius |
| Chemical Substances | carbon tetrachloride (CCl4), potassium permanganate (KMgO4), silver chloride (AgCl) |
| Applications | water desalinization, glass manufacturing, bulk metallic glass |
Prerequisites
Before starting this session, you should be familiar with:
- The Bonding and Molecules module (Session 7 through Session 12)
- Chemistry of glasses (Amorphous Materials module), in Session 21 and Session 22
Learning Objectives
After completing this session, you should be able to:
- Define what makes an "aqueous solution."
- Explain the behavior of ionic compounds in water.
- Calculate molarity of a solution.
- Predict the solubility of different combinations of solutes and solvents, given the chemical properties of those compounds.
- Explain the dynamics of solutions using the concepts of equilibrium constant, solubility product, and common ion effect.
Reading
| Book Chapters | Topics |
|---|---|
| [Saylor] 13.1, "Factors Affecting Solution Formation." | Forming a solution; roles of enthalpy and entropy |
| [Saylor] 13.2, "Solubility and Molecular Structure." | Factors affecting solubility; molecular interactions in liquids; solutions of solids; solubility of ionic substances |
| [Saylor] 13.3, "Units of Concentration." | Molarity and mole fraction as measures of concentration |
| [Saylor] 17.1, "Determining the Solubility of Ionic Compounds." | Solubility product Ksp, ion product, common ion effect |
| [Saylor] 17.4, "Solubility and pH." | Acid-base equilibriua effects on solubility; basic, acidic, and amphoteric oxides; using pH for selective precipation |
Lecture Video
> Download from iTunes U (MP4 - 216MB)
> Download from Internet Archive (MP4 - 216MB)
Resources
Lecture Summary
This session surveys the chemistry of aqueous solutions, in which ionic compounds are dissolved in liquid water as a solvent. The rule "like dissolves like" means that a solute tends to dissolve best in a solvent with similar chemical structure. Molarity is defined as a measure of solubility, and conventions for classifying substances as soluble and insoluble are presented. The session also defines and examines the importance of equilibrium constant K and solubility product Ksp, and the common ion effect.
The class ends with a discussion of the properties of amorphous glasses, including recent advances in fabrication and product manufacturing using bulk metallic glasses.
Homework
Textbook Problems
| [saylor] Sections | Conceptual | Numerical |
|---|---|---|
| [Saylor] 17.1, "Determining the Solubility of Ionic Compounds." | 1, 6 | 2, 3, 10, 18, 21 |
For Further Study
Supplemental Readings
Chang, Kenneth. "The Nature of Glass Remains Anything but Clear." The New York Times, July 29, 2008.
People
Svante Arrhenius — 1903 Nobel Prize in Chemistry