1. Unit 1 Lecture 4: Solute/Solvent Interactions
The student is able to draw and/or interpret representations of solutions that show the interactions between the solute and solvent.

2. Mixtures A physical blend of two or more pure substances
in any proportion
each substance retains its individual properties
can be separated by physical means.

3. Two Type of Mixtures
Heterogeneous – species retain their individual properties and do not mix smoothly throughout
Suspensions – have large particles that if left undisturbed will settle out (muddy water, paint)
Colloids – have very small particles that do not settle out (milk, blood)
Homogeneous – solution where solutes completely dissolve into a solvent and individual species are indistinguishable.
Solutions - Can exist in the solid, liquid or gaseous phase depending on the state of the solvent

4. Solution Examples
Air – O2, N2, H2O, CO2
Ethanol and Water
Solid solutions: dental fillings, 14K gold, sterling silver
Liquid solutions: saline, vinegar, sugar water
Gas solutions: the atmosphere, anesthesia gases

5. Solvent
Substance that dissolves a solute to form a solution; most plentiful chemical species in the solution

6. Solute
One or more chemical species dissolved in a solution.

7. Demo: Intermolecular Attractions
Water
Isopropyl alcohol
Acetone

8. Mini-Labs
Get into 2 lab groups and begin performing the mini-lab experiments.
You have 20 minutes to complete the activity.
Each team will briefly summarize their findings to the class and describe their particular phenomenon.

9. Elevation Boiling Point
Boiling occurs when the pressure of the evaporating solution is equal to atmospheric pressure.
Solvent particles interact with the solute particles causing fewer solvent particles from escaping the solution.
More energy is needed to cause the solution to boil.

10. Freezing Point Depression
Freezing occurs when solvent particles arrange and organize themselves in an ordered solid.
Solute particles get in the way of solvent particles preventing the solution from freezing.
Colder temperatures are required to cause the solution to freeze.