精華區beta NTU-Exam 關於我們 聯絡資訊
2002/11/21 Total:117 I)Simple choice(only one correct answer for each question):4%*12=48% 1)Rank in order of increasing acidity of the following compounds: A:2,4,6-trinitrophenol; B:1-Propyne; C:(CH3)3NHCl; D:O2NCH2CH2OH (A)A>B>C>D (B)B>A>C>D (C)B>C>A>D (D)A>C>D>B 2)Which of the following statement is CORRECT? (A)Compound 5,8-bis(1-methylethyl)dodecane has 2 tertiary Hydrogens (B)Compound 4-(1-ethylpropyl)-2,3,5-trimethylnonane has 5 tertiary Hydrogens (C)Compound 2,6,6-trimethylbicyclo[3,1,1]hepta-2-ene has 3 secondary Hydrogens (D)The most stable structure of 2,3,4,6-tetrachloro-1-tert-butylcyclohexane shown below has 2 chlorine atoms at the equatorial positions (有附圖) 3)about Newman projection (圖略) 4)Which of the following could not be a resonance structure of CH3NO2? (A) ‥- (B) ‥- (C) (D) ‥- H :O: H :O: H H O: | +╱.. | 2+╱..- | + .. | +╱‥ H─C─N═O H─C─N─O: H─C─N═O H─C═N     | ‥   | ‥     | ╲‥ -    ╲‥ H H H :O: O─H 5)A split peak for the IR absorption due to bond streching is observed for the carbonyl group in which of these compounds? (A) O (B) O (C) O (D) O O ║ ║ ║ ║ ║ CH C─OH CH C─CH CH CH C─NH CH C─O─CCH 3 3 2 3 3 2 3 3 6)Rank in order of increasing vibration frequency of the following stretchings in the frame R O CH ╲ ∣3 R—C≡N C═O R—C—NH R—N—H ╱ 2 I R II III IV (A)I>III>IV>II (B)IV>I>II>III (C)II>III>I>IV (D)III>II>I>IV 7)Quantify the difference in stability of the two structures shown below CH | 3 ∕╲/—CH ∕╲/ H C—╱╲∕ 3 H C—╱╲∕ 3 3 I II (A)I is more stable than II by 7.5 KJ/mol (B)I is more stable than II by 15 KJ/mol (C)II is more stable than I by 7.5 KJ/mol (D)II is more stable than I by 15 KJ/mol 8)How many stereocenters are there in the anabolic steroid methenolone? (圖略) (A)4 (B)5 (C)6 (D) 7 25 。 9)What can be said with certainty if a compound has [α]D = -9.25 (A)The compound has the (S) configuration (B)The compound has the (R) configuration (C)The compound has no plane of symmetry (D)The compound has an optical purity of less than 100% 10)about (S) config. selected (略) 11)Which is the best sequence to prepare 5-methyl-2-hexyne? (A) CH3 (B) | CH3 NaOH BrCH2CHCH3 | NaNH2 CH3Br H3C-C≡CH ──→─────→ HC≡CCH2CHCH3 ──→──→ (C) CH3 (D) | CH3 NaNH2 BrCH2CHCH3 | MeONa CH3Br H3C-C≡CH ──→─────→ HC≡CCH2CHCH3 ──→──→ 12)Which statement is true? (A)butane and cyclobutane are consitional isomers (B)E-1,2-dichloropropene and trans-1,2-dichloropropene are different compounds (C)ethane contains numerous conformational isomers including eclipsed and staggered forms (D)The chair conformational isomer of cis-1,2-dichlorocyclohexane must display two chlorine atoms at equatorial position II)By viewing from C2-C3 axis, draw Newman projections for the two eclipsed and staggered conformational isomers of 2-methylbutane. Indicate the one has the highest energy and the one has the lowest energy. (8%) III)Please draw the following orbitals (5%*2=10%) (A)σ bonding & σ* (B)π bonding & π* IV)Allene, H2C=C=CH2, is somewhat unusual in that it has two adjacent double bonds. Draw a picture showing the p orbitals involved in the π bonds of allene(please indicate the p orbital axis). Is the central carbon atom sp2- or sp-hybridized? (6%) V)Sodium bicarbonate, NaHCO3, is the sodium salt of carbonic acid(H2CO3), pKa =6.4. Which of the following substances will react with sodium bicarbonate? (5%) __ O O O // \\__OH O ║ ║ ║ ﹨ ∕ ║ H3C-C-CH3 H3C-C-CH2-C-CH3 ═ H3C-C-OH Acetone,pKa=19 2,4-pentanedione,pKa=9 Phenol,pKa=9.9 Acetic acid,pKa=4.5 VI)Please write three kinds of intermolecular interations and explain how they can affect physical properties of molecules. (9%) VII)Please explain the following terms (4%*4=16%) (A)Frontier Orbitals (B)Protic solvent (C)Leveling effect (D)Lewis Acid VIII)Draw strustures of the following compounds: (3%*5=15%) (A)1-bromospiro[4.5]decane (B)sec-butanol (C)Trans-bicyclo[4.3.0]nonane (D)tert-butylcyclohexane in chair form (E)(R)-1-bromo-2-butanol 選擇題解答:DBCDD BADC(CorD) BC -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.169.27.223 ※ 編輯: japwoon 來自: 61.229.202.118 (11/20 16:18)