1 IMF KE IMF > KE IMF < KE Increasing EN Special cases: - PDF document

The Interstate Highway SystemIn 1919, a convoy of army trucks was sent on a journey across the United States, from Washington to San Francisco, to test the efficiency of the roadway system in case of an emergency. It took 62 days for the convoy to cross the nation, underlining the needs for better road infrastructures. The origins of the Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate System, can be traced back to 1941 when President Franklin D. Roosevelt appointed a National Interregional Highway Committee to evaluate the need and potential for a national highway system. A system of 33,900 miles of rural routes, plus an additional 5,000 miles of auxiliary urban routes was recommended. Funding for the system was first authorized in 1952, but the construction of such a massive public and freely accessible infrastructure was beyond the means of the state and federal governments. The first highway segments were thus toll roads. It was under President Eisenhower that the question of how to fund the Interstate System was resolved with the enactment of the Federal-Aid Highway Act of 1956, which in addition provided design standards for the system. Construction then proceeded rapidly and by 1991 the system was considered officially completed. As of 2010, the Interstate system totaled more than 47,100 miles. https://people.hofstra.edu/geotrans/eng/ch3en/conc3en/map_interstatesystem.html 1

IMF  KE IMF > KE IMF < KE Increasing EN Special cases: (1) EN(O) > EN(Cl) 2

Special cases: Special cases: (1) EN(O) > EN(Cl) (1) EN(O) > EN(Cl) (2) EN(H)  EN(C) Identify the most important intermolecular force for: Cl  I Br  Br A. ion-ion __________________ B. dipole-dipole C. London dispersion Predict which of these molecules has the highest BP? __________________ 3

Are SiF 4 and SF 4 polar or nonpolar? SiF 4 SF 4 A. polar polar B. nonpolar polar C. polar nonpolar D. nonpolar nonpolar Are AsF 5 and BrF 5 polar or nonpolar? AsF 5 BrF 5 A. polar polar B. nonpolar polar C. polar nonpolar D. nonpolar nonpolar 4

Which molecule is expected to have the highest boiling point?  52.8  C A. AsF 5 40.25  C B. BrF 5 Recall: Are SO 2 and SO 3 polar or nonpolar? SO 2 SO 3 A. polar polar B. nonpolar polar C. polar nonpolar D. nonpolar nonpolar 5

The partial negative charge on SO 2 is... A. on the sulfur atom’s side. B. on the oxygen atoms’ side. http://chemwiki.ucdavis.edu/Wikitexts/UCD_Chem_2A/ChemWiki _Module_Topics/Chemical_Bonding/Electrostatic_Potential_maps 6

What IMF is responsible for BP (  C) SO 3 having a  10 SO 2 higher BP than SO 3 45 SO 2 ? A. ion-ion B. dipole-dipole C. London dispersion Which molecule is expected to have the highest boiling point?  38  C A. SF 4  64  C B. SF 6 C. ?????? 7

What IMF is responsible for SF 4 having a higher BP than SF 6 ? A. ion-ion B. dipole-dipole C. London dispersion The straight-chain isomer allows closer contact between the C 4 H 10 molecules. 8

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0.87 atm 10

water benzene 11

Identify the strongest intermolecular force for: CH 3 OCH 3 CH 3 CH 2 OH __________________ __________________ Predict which of these compounds has the higher VP? A. CH 3 OCH 3 B. CH 3 CH 2 OH 12

1 s 15 s 35 s 55 s https://www.youtube.com/watch?v=hih0dEYxi3U Recall… water benzene 13

hexagonal cubic close-packed close-packed 14

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Three Types of Cubic Unit Cells Each corner atom Each edge atom is Each face atom is is shared among 8 shared among 4 shared among 2 unit cells. unit cells. unit cells. So a corner atom So an edge atom So a face atom contributes 1/8 of contributes 1/4 of contributes 1/2 of an atom per unit an atom per unit an atom per unit cell. cell. cell. 16

How many atoms in a face- centered cubic cell? A. 4 B. 7 C. 8 D. 12 E. 14 How many chloride ions in the NaCl unit cell? A. 2 B. 4 C. 6 D. 8 E. 10 17

Which is denser? A. water, H 2 O( l ) B. ice, H 2 O( s ) Yesterday, upon the stair, "Antigonish" I met a man who wasn’t there by Hughes Mearns He wasn’t there again today 1899 I wish, I wish he’d go away... When I came home last night at three The man was waiting there for me But when I looked around the hall I couldn’t see him there at all! Go away, go away, don’t you come back any more! Go away, go away, and please don’t slam the door... (slam!) Last night I saw upon the stair A little man who wasn’t there He wasn’t there again today Oh, how I wish he’d go away 18

Extended 3-D Unit cell showing 3-D structure of ice structure of diamond Solubility and Colligative Properties: Our first glimpse of entropy 19

Concentration Units: Definitions and Uses Molarity ( M ) mol of solute / L of solution solution stoichiometry, Henry’s law, osmotic pressure, equilibrium calc Parts by Mass mass of solute / mass of solution e.g. ppm, ppb (% is pph); especially important in environmental Parts by Volume volume of solute / volume of solution used, but not very useful (volume is not additive) Mass per Volume mass of solute / volume of solution important in medicine; in dilute aq soln, g/100mL  %, mg/L  ppm Mole Fraction ( X ) mol of solute / (mol of solute + mol of solvent) Raoult’s Law Molality ( m ) mol of solute / kg of solvent freezing point depression, boiling point elevation 20

Which of these concentration units will vary with temperature? A. parts by mass, or mass fraction ( mass solute / mass solution ) B. mole fraction ( mole solute / total moles of solution ) C. molarity ( mole solute / liters of solution ) D. molality ( mole solute / kg of solvent ) 21

If less than 1 gram of the substance will dissolve in 100 milliliters (or 100 g) of solvent, the substance is considered insoluble. If more than 10 grams of substance will dissolve in 100 milliliters (or 100 g) of solvent, the substance is considered soluble . www.mpcfaculty.net/mark_bishop/ solubility _entropy.htm What is the concentration of water in water? A. less than 10 M B. around 20 M C. around 30 M D. around 40 M E. greater than 50 M 22

http://academic.pgcc.edu/~ssinex/struc_bond/solubilities.htm Which will be least soluble in water… A. Vitamin A B. Vitamin B C. Vitamin C 23

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very ??? similar Saccharine Sodium Cyclamate Sucralose Dulcin Aspartame 25

The Lipinski's Rule of Five states that an orally- active drug should respect:  a molecular weight under 500 Daltons,  a limited lipophilicity (expressed by Log P < 5, where P = [drug] org /[drug] aq )  max 5 H-bond donors (expressed as the sum of OHs and NHs),  max 10 H-bond acceptors (expressed as the sum of Os and Ns). http://www.cedricbrule.com/page.asp?rec=237&dossier=18 26

How does solubility depend on temperature? A. increases with increasing temperature B. decreases with increasing temperature C. stay the same D. well, it depends... Figure 11.17 This graph shows how the solubility of several solids changes with temperature. 27

NH 4 NO 3 (s)   (aq) NH 4 + (aq) + NO 3 This process is A. endothermic,  H > 0 or B. exothermic,  H < 0 How does solubility depend on temperature? A. increase B. decrease C. stay the same How about pressure? You already considered how the solubility of a gas A. increase….etc. depends on pressure (Henry’s law). 28

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Recall.... 30

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