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Spring 2008 Test 1 - CHEM 228 test 1 spring 2008 Dr Wells I...

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Unformatted text preview: CHEM 228 test 1 spring 2008 Dr. Wells I Score = opscan * 86/21 + essay= Z_l *86i‘21 + l_:i_— loo. “0+ b“ . Honor Code Reminder: it is cheating to look at someone’s test during the exam. It is also cheating to allow someone to look at your test during the exam. It is a shame that I even have to write this, but recently there has been a rash of cheating and it must stop. This examination will be video recorded. Anyone found cheating will be assigned a grade of F x for the coursellll You may appeal to university the Honor Court. You should know that the video will be used in that proceeding. Fri iwfi's . El Some data: m .-._ 3 k in E ”:m 3 is 3:23 I . . " m ‘ “( Nslkflflprnxlmate Chemical Shitt Ranges |—— ..... “"T—F"—“-—~ ii LEE: — ‘l'l m z 9 ‘ ".‘v CJ —"‘— -——_'..__.._‘___JL.__'4i l in..." ‘ 'j E C“ ‘ P a .. : le—k-fi‘ ‘1 3.1:- 9“ : ‘2 i 1" l [ ___| F drillii [L4 l :H j i it‘d "' _.:"_"” J [ :PN‘LJJ :., i _i i "'3' " i L H i [3 ’ 3 ”c 20 -—.- T T ' "F - 7—1 -1- —v—-w-— 1 '3; $3 34 0 130 150 140 120 we so so 40 2'0 0 a __ _ _ h-fppml ,_ ._ M1 5"" mini—us : ’“‘ i i t. :13 ’i' . ..._ M» " '0 i5 9: iii 0 fl :‘E’i .'J __ gar ': :'.I-~ sii 8 9 L3: ‘34 .: iii»: 1.2:“ if :1 T: m | " E' ' I "E 3 3 H: o 11‘ E 3 E E _: El Li if: g'J-j TL if ‘29-! f7. :3 .“T: 3 Legi— I :... i i iii 3-5"? N ‘l sE3L .. E 3:: g 3 g 3 - .W": "E‘ ‘c 's E. "T m...“ ..... *2 Emma“! _ s E" _ 1...! I. On the next page: (9 pomts) 2?. “ “”3; V.- - DiSCuss key features of the IR spectrum. $3 33 D i3 - Draw the predicted 1H NMR spectrum. ‘5? 3 - Label the different types of protons (i. e. chemically equivalent) in the compound with letters (a, b, c, . . .) - Indicate which protons are responsible for each resonance (by letter). - Draw the resonance at the correct (estimated) chemical shift (8) - Draw the correct splitting pattern for each resonance (i.e. doublet, triplet, quartet . . . ) - Indicate integration with relative numbers of protons above each resonance. (i.e. 1H, 2H, 3H . . .) 0 Draw the predicted 13C NMR spectrum. - Label the different types of carbons (i. e. chemically equivalent) in the compound with letters (A, B, C,. . .) - Indicate which carbons are responsible for each resonance (by letter). - Draw the resonance at the correct (estimated) chemical shift (6) - Include the DEPT information above each peak (i. e. C, CH, CH2, CH3) Essay A (9 points) Discuss IR: Essay B. Mystery compound: (5 points; all or none) The molecular formula is CgHe. Examine the spectra and draw the compound. IR spectrum 5|] lllH$I1HTMEEI 2| MOM 3&5?)th ban—25c»?— 1. For a given wave, as the wavelength increases its energy (3) a. remains constant (9 decreases c. increases 2. When molecules absorb infrared energy . E 3: h C— @ natural atom movements are stimulated --""' b. electrons are promoted to excited states a c. the spin of the nucleus is flipped d. more stable carbocations are formed e. chromophores are extended 3. When molecules absorb radio waves a. natural atom movements are stimulated b. electrons are promoted to excited states 6 the spin of the nucleus is flipped d. more stable carbocations are formed e. chromophores are extended 4. Acetylene (ethyne) has a small peak near 2100 cm'] . Propyne has a larger peak at 2100 cm" because a. propyne has an oxygen b. prOpyne is an internal alkyne © propyne is an asymmetric alkyne d. propyne has more hydrogcns e propync is a terminal alkyne ’L +A~L l lat-fl .50 \‘5 ““7" ' 5. Mass spectroscopy is accomplished by . a. comparing the mass of a sample with its mass in the presence of a magnetic field b. comparing the mass of a sample with the mass of its residue after combustion D c. bombarding the sample with ultraviolet radiation @ smashing the sample with high energy and determining the mass of the pieces e. weighing the sample after heating with infrared radiation 6. News of the week: A detailed mechanistic study shows that the SNZ reaction is not quite as simple as once thought. There seems to be an additional pathway involving a collision and a rotation of the alkylhalide before the nucleophilic attack. This study may not directly apply to most organic lab reactions because @ the study was carried out in the gas phase b. the study was carried out in the solid phase c. the study was carried out using heavier isotopes of tritium and deuterium d. the study has since been refuted e. the study was carried out in the presence of a strong magnetic field 7. News of the week: A research group has made a cage-like molecular structure that contains antracene and copper that can . a. convert light in to electricity better than most silicon based systems (1» store methane at high densities & c. deprotonate ketones and aldehydes d. isomerizes cis—alkenes to trans selectively e. superconduct at a relatively warm —330 C l4 8. A four-carbon alcohol that is chiral is . ‘ )é a. 1~butanol _ (J ® 2~butanol C/r‘r C’-—C, c. 2-methyl—l—propanol l d. 2-methyl-2-propanol l4 e. none ofthese 9. Using dilute aqueous sulfuric acid to make alcohols from alkenes can lead to mixtures of products because _. a. high pressures are required b. high temperatures are required 0. sulfuric acid behaves as a nucleophile too /’ d. primary alcohols are formed rapidly .low order carbocations often rearrange to higher order carbocations 10. The most likely product of the reaction below is if C 3 H 9 C=C ‘—“‘“‘——“—"——" ' H3C CH3 /H H30 o—o CH3 H30 FY \CQC/ \(i_i3/ Hac\i iii/CH3 C=0 \/ H30/ ®\CH3 H30/ B \CH3 /C—C\ H30 D H30 C CH3 1 1. The most likely product of the reaction below is H30 H 1) THF:BH3 / 2) H202, OH' 9 o: —)- O / \ H3O CH3 ‘% H 0/ H H H H O 0 H HC (5H H 0/ \ \” \i—l/ \ci—c/ ”fix/Ag “N HC/ A \CH Hall/63> \CH3 H3C/ \CH3 /C—C\ (3 H30 D CH3 12. Which of the following would not contain a quartet in its 1H NMR spectrum? H H 3’ Br {‘9‘ka {Wk}- 13. FT NMR instruments are filled with liquid helium so that _ . a. the magnetic will float the electromagnet will superconduct c. the sample will not overheat {g d. the sample will remain in the solid state e. extra neutrons are absorbed 14. The Markovnikov rule is based on a. the amount of water present b. stability of alkene c. steric crowding directs nucleophile to less crowded region d. planar intermediates yield racemic mixtures ® formation of the most stable carbocation 15. Reaction of cis-Z-butene with a peroxy acid followed by aqueous sodium hydroxide yields a. a meso compound a racemic mixture 0. an aldehyde _ n ® {'7 )4 rgwi ‘- I d. a ketone e. a primary amine ‘4 -- d“ H c) M V‘ m o H 0 ;( _____ -E> A 9 F9 ‘4 “‘7” \ CH gs 5-D f) w 3 I”! Questions 16 and 17 are from Dr. Jung’s polymer lecture. [’1 16. A portion of a syndiotactic polymer is 17 . A polymer that can be remelted and remolded is called a. isomaleable b. isoductile c. thermohelic Q @ thermoplastic e. thermo setting Check out the wild reaction sequence below for questions 18-21 1)Hg(0Ac)2 2)NaBEg,OH' X TsCUbase Y NaOMe Z 13. Compound X is most likely . QQQQQ OH HO OH H0 19. Compound Y is most likely AQRQQQ 20. Compound Z is most likely EflQQQQ OMe H Me 21. Compound W is would have lines in its l3'C NMR spectrum. a. 1 b. 3 (94 d. 6 e. ? : The end . . . I’ll see you TuesdayE! Sfizq Em 0° 3W ...
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