Lesson 10: 3.10 Solubility
Duration of Days: 1
Lesson Objective
Explain the relationship between the structures of solutes and solvents and the solubility of a solute in a solvent.
Why do some substances mix effortlessly while others form distinct, separate layers?
What energetic changes occur during the three distinct stages of solution formation?
Solubility
Miscible
Immiscible
Hydrophobic
Hydrophilic
Solvation Energy
Learning Objective 3.10.A; Suggested Skill 4.A (Model Analysis).
Explores the molecular basis of the phrase "like dissolves like." Students must understand that for a solution to form, the new solute-solvent interactions must be strong enough to overcome the energy required to separate the solute-solute and solvent-solvent particles.
Support: Use a color-coded chart mapping polar/ionic solutes to polar solvents (soluble) and nonpolar solutes to nonpolar solvents (soluble), highlighting mismatched pairs as insoluble.
Extension: Provide a structures sheet of vitamins (e.g., Vitamin A vs. Vitamin C). Have students classify each as fat-soluble or water-soluble based on the ratio of polar functional groups (-OH) to nonpolar carbon chains.
Predict whether iodine crystals, I2(s), will be more soluble in water (H2O) or in carbon tetrachloride (CCl4). Justify your prediction by describing the intermolecular forces involved between the solute and both solvents.