Ch. 2 Power Points below (including plenty that I would have shown today, but did not get to).

Transcription

1 Lewis Structure + Functional Group Quiz Average: 77. The quizzes are easier than the tests. If your score was or below, need to do more practice problems/studying and/or adjust your class/work/life schedule accordingly Nomenclature 1 Quiz - Monday class time - Learn the Nomenclature 1 Memorization Handout - note that the linear alkyl and alkoxy groups shown are there to demonstrate the general pattern, but that it could be ANY alkyl or alkoxy group. Today I could not get the projector to turn on, so there are no notes to post today since they were on the board. I did post my whole Ch. 2 power point on the Lecture Notes page for today, since there are some things there that you may find useful. One thing I did not state explicitly today is that the stronger each type of intermolecular force and/or the more different types of intermolecular forces that are present, the higher the boiling or melting point. We'll touch on solubility on Friday, but the more similar the intermolecular forces are in terms of strength and type, the more likely two molecules would have favorable solubility. HW#4 - Ch2 Smartwork - Due 10 AM HW#5 - Nom 1 Smartwork - Due 11:59 PM Note that this is a CHANG from the original due date set - regardless of what smartwork says - this is the due date. Test 1 will be on Ch.1, Ch.2, and Nom 1 - Updated test date - WDNSDAY - 9/20 (set BACK to the original date) Office hours Thursday AM PM; Friday 9-10 AM, or by appointment. Kaitlyn's office hr 1st floor library Thursday 2:30-3:30 pm We finished most of Ch. 2 today. We will spend most of the class period on Friday on Nomenclature - answering the questions you have about the IUPAC video & problems on the handout, and going over the radicofunctional method for alkyl halides, alcohols, and ethers. Textbook problems & reading: Should have read all of Ch. 2 and Nom. 1 by this point Karty Textbook problems based on today's lecture (lots of good problems on this stuff!): 2.3, 2.4, 2.4, 2.7, 2.8, 2.9, 2.10, 2.13, 2.14, 2.15, 2.17, 2.19, 2.22, 2.24, 2.26, 2.27, 2.34, 2.35, 2.40, 2.42, 2.43, 2.46, 2.47, 2.48, 2.51, 2.54, 2.58, 2.61, 2.65, 2.67 Ch. 2 Power Points below (including plenty that I would have shown today, but did not get to).

2 Five Basic Arrangements of Regions of lectron Density # Regions of e- Density 3-D Arrangement 180 Possible Molecular Shapes 2 linear A * linear 3 trigonal planar A 120 * trigonal planar * bent 4 tetrahedral A * tetrahedral * trigonal pyramidal * bent 5 trigonal bipyramidal axial position A equatorial positions * trigonal bipyramidal * distorted tetrahedral (or seesaw shaped) * T-shaped * linear 6 octahedral A 90 * octahedral * square pyramidal * square planar

3 Basic Principles of VSPR Theory VSPR & Geometries for Organic Compounds # of regions of e- density lectronic Geometry Molecular Geometry Atoms) 2 linear (180 ) 3 trigonal planar (120 ) 4 tetrahedral (109.5 ) * Modified from the chart in the textbook

4 Dipole Moment con>nued

5 Vector Addi>on of Tetrahedral Dipole Moments

6 5

7 You Try: Determine molecular polarity of the following molecules. Draw an arrow indicaxng the overall dipole moment of the molecule, or use δ symbols to indicate parxal charges. 6

8 Dipole-Dipole

9 lectrosta>c Poten>al Map of Dipole-Dipole Interac>on

10

11 London (Dispersion) Forces Gecko Feet Reference: h]p:// disc_images.jsp? cntn_id=112442&org=nsf

12 Hydrogen Bonding

13 Hydrogen Bonding

14 Bonding Forces Intermolecular Forces Increasing Strength 13

15 Intermolecular Force Comparison: IMF effects on solubility: Like dissolves like

16

17 2.6 Mel>ng Points, Boiling Points, and Intermolecular Interac>ons MelXng points and boiling points can provide a lot of informaxon about intermolecular interacxons.

18 Strategies Rank each group by boiling point, according to the relative strengths of the intermolecular interactions.

19 Strategies con>nued 3. Rank the boiling points within each group. 4. Arrange them all together. 5. Check?

20 Water Solubility of Various Compounds Below are the water solubilixes (g/100 g H 2 O) of some selected alcohols.

21 Solubility of Benzene in Var. Solvents Solubility: QualitaXve indicaxon of solubility in common solvents. AbbreviaXons are: i=insoluble; sl=slightly soluble; s=soluble; vs=very soluble; msc=miscible; dec=decomposes Data for Benzene: sl H2O; msc ethanol, diethyl ether, acetone, chloroform; s CCl 4 Reference: CRC online via Campbell s Wiggins Library, Accessed 9/16/15

22 Pro>c and Apro>c Solvents con>nued

23 The Solubility of Ionic Compounds: Ion Dipole Interac>ons and Solva>on con>nued

24 Solva>on con>nued

25 2.9 Pro>c and Apro>c Solvents con>nued

26 Steric Hindrance con>nued

27 2.10 Soaps and Detergents The cleaning ability of soaps and detergents depends on intermolecular interacxons. Salts of fa]y acids, such as RCO 2 Na + or RCO 2 K + are the compounds responsible for the cleansing abilixes. R is a long hydrocarbon chain (~12-18 carbons). xamples include potassium oleate and sodium palmitate.

28 Soaps: FaUy Acids con>nued The carboxylate anion has a hydrophobic end and a hydrophilic (red oxygen atom) end.

29 Micelles con>nued

30 mulsifying dirt, grease, and oils The nonpolar tails of soaps dissolve in a parxcle of dirt, grease, or oil. The ionic head groups on the outside make the parxcle water soluble.