Inter molecular Forces (l) & (s) phases: Molecule-molecule Molecule-ion

1. Intermolecular Forces (l) & (s) phases: Molecule-molecule Molecule-ion

2. Suggested Reading: 1) Page 380, I suggest you read the first paragraph in section 8.8 if not the entire section. 2) Review Example 8.12 on pg 384 to make sense of why NH3 is more polar than NF3, which at first seems odd. 3) Read the bottom of pg 558 beginning with, “When a polar…” to “…dipole-dipole attraction.”4) Read three paragraphs on pg 562, starting with “There is an unusually strong…” to “…(Figure 12.7).”5) On pg 565-567, read the two sections: “Dipole/Induced Dipole Forces” and “London Dispersion Forces: Induced Dipole/Induced Dipole”.

3. 12.1 Know the level of intermolecular forces for each state of matter, s, l, g. Which has the most and which has none?

4. PLAY MOVIE

5. Q: What makes molecules “stick” together in the liquid (and solid) state? A: The opposite ends of their dipoles: opposites attract…..and like polarities “stick” to like polarities.

6. Recall molecular polarity…?

8. Opposites attract…..and like polarities “stick” to like polarities.

11. Pg 563, Exc. 5.2-5.4 EOC 1, 3, 5, 7, 17

12. FORCES INVOLVING INDUCED DIPOLES Formation of a dipole in two nonpolar I2 molecules. Induced dipole-induced dipole

14. PLAY MOVIE

15. FORCES INVOLVING INDUCED DIPOLES How can non-polar molecules such as O2 and I2 dissolve in water? The water dipole INDUCES a dipole in the O2 electric cloud. Dipole-induced dipole

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17. Different Levels of Molecular Polarity C B A H D E

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19. Dipole-Dipole

20. H-Bonding

21. H-Bonding

22. H-Bonding Between Two Methanol Molecules - + - H-bond

23. H-bond H-Bonding Between Methanol and Water - + -

24. H-Bonding Between Ammonia and Water - + - H-bond

25. Base-Pairing through H-Bonds

26. Hydrogen Bonding in Biology Hydrogen bonding and base pairing in DNA. PLAY MOVIE See ChemistryNow, Chapter 12

27. Ion-Dipole

28. PLAY MOVIE

29. C4H10 C3H8 C2H6 CH4

31. Pg 563, Exc. 5.2-5.4 EOC 1, 3, 5, 7, 17

32. Boiling Liquids PLAY MOVIE PLAY MOVIE Liquid boils when its vapor pressure equals atmospheric pressure.

33. ether alcohol water O O O C H H C H C H H 2 5 H 5 2 5 2 dipole- extensive dipole H-bonds H-bonds increasing strength of IM interactions LiquidsSee Figure 12.17: VP versus T 4. If external P = 760 mm Hg, T of boiling is the NORMAL BOILING POINT 5. VP of a given molecule at a given T depends on IM forces. Here the VP’s are in the order

34. From Chapter 13.6 Know how to interpret phase diagrams

35. Phase Diagrams

36. TRANSITIONS BETWEEN PHASESSee Section 13.6 • Lines connect all conditions of T and P where EQUILIBRIUM exists between the phases on either side of the line. • (At equilibrium particles move from liquid to gas as fast as they move from gas to liquid, for example.)

38. Phase Equilibria — Water Solid-liquid Gas-Liquid PLAY MOVIE PLAY MOVIE Freezing/Melting Condensation/Evaporation Gas-Solid PLAY MOVIE Deposition/Sublimation

39. Phase Diagram for Water Liquid phase Solid phase PLAY MOVIE PLAY MOVIE PLAY MOVIE Gas phase

40. Triple Point — Water At the TRIPLE POINTall three phases are in equilibrium. PLAY MOVIE

41. CO2 Phase Diagram

42. CO2 Phases Separate phases Increasing pressure More pressure Supercritical CO2 See Figure 13.20