1. Solutions

2. Vocabulary Solute Solvent Saturated solution Unsaturated solution Supersaturated solution Molarity

4. Solution Formation Depends on tendency toward mixing (driven by entropy) types of IMFs in the solute and solvent

5. Solution Formation Three interactions involved: –Solvent-Solvent –Solute-Solute –Solvent-Solute A solution forms if the solvent-solute interactions are similar to or stronger than the solvent-solvent and solute-solute interactions

8. Occurs in three steps: 1.separation of solute molecules Solution Process

9. Occurs in three steps: 1.separation of solute molecules 2.separation of solvent molecules Solution Process

10. Occurs in three steps: 1.separation of solute molecules 2.separation of solvent molecules 3.solvent and solute mix ΔH soln = ΔH solvent + ΔH solute + ΔH mix Solution Process

12. ΔH soln = ΔH solvent + ΔH solute + ΔH mix ΔH solvent is positive (endothermic process) ΔH solute is positive (endothermic process) ΔH mix is negative (exothermic process) Sign of ΔH soln depends on magnitude of ΔH mix compared to magnitude of ΔH solvent + ΔH solute

14. What factors affect dissolving? Stirring / agitation and surface area can affect the RATE of dissolving (but not amount) Structure/nature of solute and solvent “Like dissolves like”

15. What factors affect dissolving? Pressure –No effect on a solid or liquid solute –For gases  solubility with  pressure

16. What factors affect dissolving? Temperature –For a solid solute –For gases  solubility with  temp  solubility with  temp

17. Solubility Curves (Solids)

18. Solubility Curves (gases)

19. Effect of Particle Size solution – very small particles; <1 nm suspension – particles have at least one dimension larger than ~1000nm. colloid – intermediate-size particles; one dimension between 1-1000nm.

20. Colloid Particles in a colloid do not settle because of brownian motion, the constant, erratic movement of the particles. This motion is enough to keep the intermediate-sized particles in solution.

21. Effect of Particle Size How do you tell the difference between a solution, a colloid and a suspension? Suspension: particles are visible can be separated from solution via filtration How do you differentiate a colloid and solution?

22. Effect of Particle Size Tyndall Effect – scattering of light by colloid particles (and suspension particles) Shine a light on your sample. If you can see the beam of light’s path through the sample, it is a colloid.

23. Tyndall Effect