2009_Fall_3305-1-A[1].pdf

October F-fi;l cHf,M 3305-003/CHf,M 5323 003 Organic Chemistry I Dr. Dongmei Zhang Name: Exam # I (fO0pts) Last name, First Name I't 2009 Score: Multiple choice Exam paper Total Copynght 2009, Dongmei Zhang lnstructions: 1. PRINT your name, bubble yoqr ID number (B number) and exagn form on the scanfion form 2. Mark your answer to the multiple choices questions on the scantron form 3. LEGIBLY write your answers to the remaining questions on this exam paper 4. You can use the back of exam paper as scratch paper I. Mutiple choices (40 pts, 2 pts each. Mark your answer on the scantron form): D l. How many valence electrons does N atom have?r)'// A.6 8.5 C.4 D.3 2. Which of the following correctly describes the electrons in carbon? A. 3.r electronst3 p electrons B. 2 ls electrons;4 2p electrons C. 2 ls electrons; 2 2s electrons; 2 2p electrons D. 2 ls electrons; 2 2s elecfions; 4 2p electrons 3. The formal charge on oxygen in the following structure is: H-p:-cH2cH3 8.0 c.-l D. -2 D.2p They are isomers. They are resonance structures. Neither of the choices is correct. 1' 4. Which of the following orbital has the most s charactor?\- A. rp' B. ,pt c.sp A 5. How are the molecules in the fbllowing pair related?r\ Hrc'-- . ..o-,^. ..cl Hoc... -.o--c1i c1z - -cH- -cH. CI i)I ,-'/ A. +l A. B. C. A 6. Which of the following is the strongest acid?/\ A. H-F B. CI{rCHzCHr C. CH3CH2OH D. CH3CH2NHz t? 7. What is the hybridization of the indicated carbon 'l0 cH"-- t- cH3cH2cH2-c:cH-cH3I I A. .p' B.rpt C.sp D. ,po n 8. Does the equilibrium of this reaction lie to the left or.ight?aoo lltl O^* + cH3o =::+. + cHroH \/ A. Left B. Right C. It cannot be determined. A 9. Compare ethylene and acetylene. Which of the following statements is tnre?/\ HH \/^-t- v-v /\ HH H-C:C_H ethylene acetylene A' The C-H bond in acetylene has a higher percent s character, making it a shonger acid. B. The C-H bond in acetylene has a lower percent s character, makingit a strongir acid. C. The C-H bond in ethylene has a higher percent s character, making it a stronger acid. D. The C-H bond in ethylene has a lower percent s character, making it a stronger acid. C 10. The conjugate acid of CH3NHz is _ ? A. CHTNHz B. CHrNtf C. CH3NH3+ C I l. The molecular geometry of the following compound is? D. N' H_N_HI HA. tehahedral B. trigonal planar c. trigonal pyramidal D. linear a 12. What types of intermolecular forces exist between two molecules of this compound?\/' .'o'. ilH3C-C-CHz-CH3 A. Van der Waals B. Dipole-dipole C. Van der Waals and dipole-dipole C D. Van der Waals, dipole-dipole, and hydrogen bonding 13. A Lewis acid is also a (an) -? A. nucleophile B. Lewis base C. electrophile D. isomer P, 14. Which of the following compound has a net dipole?t/ A. CHr B. HzO C.Nz D. COz D- 15. Which of the following compounds has the lowest boiling point?n A. CHTCHzCHzCHzOH B. CH:CHzCHzCHzCHT C. CHTCHzCHzCHzNHz D. CHTCHzOCHzCHT V 16. Which of the following indicated bonds is the shortest?t// HsC-CHzpH HC-C-H H2C:CH-H CH3CHz-CH?-H A.TBC.rp.t /- 17. Which of the indicated bonds is a polar covalent bond?t- CHs I IH3C t CHI-CH2-9-CH,-Hit tl r 18. CFrOH is a stronger acid than CHTOH. This fact can be explained by which of the lbllowing L effects? A. Hybridization effect B. Resonance effect C. Inductive effect D. Hydrophobic effect L) 19. Which of the following atom is the most electronegative? A.C B.H C.Li D.N A 20. Consider the organic molecule drawn below. Describe which orbitals are used to form the f \ indicated C-C bond. (Think about the hybridizationof the bonded carbon atoms) HHHttl H-c-cT?-t ll lH A. crp2 - crps B.c"p - c"p c. c"p2 - c, D. crp3 - cp II. Write Lewis structure (label formal charge on atoms if applicable) for the following compounds/ions (6 pts,2 pts each): cHzo [czH]- .a'-\ rllt ll tt-r =f , A - C-A rt L -\-r CHTCOz- rl :Q" r lt ,. _t+-a- L-0'" I ,, ?1 IlI. Draw another possible resonance structures for the following species (4 pts): a-\. + CH,-CHLCH? ? ('rl_ * r tt- / :l_ + _ wrt2 Vn_ Lkl 2 n-6!clr;, <--> >t *. - ( _ [_ - .| | ,r : \*7{'.1. .1. I | . .HH n h IV. Draw all possible isomers for the following molecular formulas (6 pts, 2 pts each structure) a) C3H6 (two isomers) L rl> / \ (tlr-* Ul-Lrl t Crlr-- C ri> b) Draw a ketone with molecular formula CIHoO ntl\-/ ll / | ; z,lL'.1\- L- LH + V. Convert structures (8 pts,2 pts each) a). Convert to a skeletal stnrcture. (CHr)zCHCHzOH X.0,, b) Convert to a Lewis structure. CH:CHzCHO l-.t ll ;0,. rlll t1-(-C-c-N l/ h l-l cH3(cH2hcH3 /'v'\ l-t IA- r (_ I lA /'rt'-- L -- In t-\ H, I' q- C-H laa- rl Ir-t VI. Based on the following structure of vitamin C, answer the questions; (5 pts) OHI "o--A=zo\zo \/ nd 'oH l). What kind of intermolecular loyr exist between rwo molecules of Vitamin C? V&n *jez lfuar^ls itil 6\,VclQ - C\r fDl?II H r1'l,n y^, br"^ J 2) Can Vitamiir C dissolve in water, why? /as $eca^rt, ;t lvrn r.,t)-,1J Co/\ h,1,t,ray b, "i wflh vvCsu' vnJt mA'n IJ poft t-e rvwVs ll &oeg n' t lrare ^,^ck rl cr - V t lw Jl I VII. Order the following species (12 pts): l. In order of increasing acidity A. CHTCO2H (pKa:4.8); B. HzO (pKa: 15.7); C. HzCO: (pKa:6.35). C. HI P,.L . A (most acidic) 2. In order of increasing bond strength H","-J-" A. HF C B. HBr .b.A(strongest) 3. Which one of the following indicated bonds is the longest (think about hybridization of C)? H-C-C-H iI ,AnAh /\ 4. In order of increasing basicity. A. CH3COI B. CH:CHzO- C. CICHzCOz- C . P.' (most basic/strongest base) VIII. The structure of Atenolol, an antihypertensive agent, is shown below. Identifu the functional groups in Atenolol (4 pts). annide (lt,M r fi ? Uht4 IX. Match the definition to the terms. In the blank beside each term. enter the letter of the correct response from the list of possible definitions? (9 pts) t B H3C-CH2-H I C (longest)C T nluh, I Lewis acid hydrogen bond hydrocarbons hydrophilic e resonance structure nJI,---J-- nU t^ C isomers (cH3)3o+t tD)-l- ttLAdMj tfrriqonal-T- cJ Sp -- lt. I tll0 k.( cH.CH, II ) l^tr />u I ,)itTxhed a covalentbond Possible definitions: a. Sharing of electrons between two nuclei b. Transfer of electrons to form salts composed of cations and anions c. Different molecules having the same molecular formula d. Compounds composed of only carbon and hydrogen atoms e. Two different Lewis structures having the same placement of atoms but a different ilrangement of elecfrons f. The average distance between the center of two bonded nuclei g. Separationofcharges h. Water-loving i. Resistant to or avoiding water j. An electron pair acceptor k. An electron pair donor l. A proton acceptor m. A proton donor n. Interactions that exist between molecules o. The attraction between a hydrogen atom bonded to O, N or F and the lone pairs of electrons on ilO,NorF X. Predict the hybridization and geometry around each indicated atom (6 pts). H3C-6:C-Ht llybridization: intermolecular forces Geometry: (tr,1o n,J ltlran;ir,4 1 ./ t J 7" Py'^^;do"t )