作者candy79729 (candy79729)
站内NTU-Exam
标题[试题] 97上 杨吉水 有机化学一 第一次期中考
时间Sun Oct 26 16:42:56 2008
课程名称︰有机化学一
课程性质︰化学系必修
课程教师︰杨吉水
开课学院:理学院
开课系所︰化学系
考试日期(年月日)︰97.10.23
考试时限(分钟):110,之後延长5分钟 (10:20~12:10→12:15)
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注:试题中所有图片以
[PicXX]表示者,
请自
http://0rz.tw/9b52C 下载图片。(下载按钮在网页左下角)
试题:
A.单一选择题(每题三分,选十题作答,共三十分)
1.For a reversible reaction with ΔG°= 2.72 kcal/mol, what is the most
possible value for the equilibrium constant K at 297K?
(a) 0.1 (b) 0.01 (c) 0.001 (d) 10 (e) 100
2.Regarding the relative boiling points in each pair of compounds, which of
the following statements is
TRUE?
(a) CH3CH2COOCH3 is higher than CH3CH2COOH because of larger molecular
weight.
(b) Diethyl ether is higher than 1-butanol because of dipole-dipole
interactions.
(c) Tetrahydropyran
[Pic01] is lower than cyclopentanol
[Pic02] because of
hydrogen-bond interactions.
(d) Acetone (CH3COCH3) is higher than CH3OH because of larger London forces.
(e) Isobutane is higher than n-butane because of branching structure.
3.Which of the following is
NOT a resonance structure of the others?
(a)
[Pic03] (b)
[Pic04] (c)
[Pic05] (d)
[Pic06] (e)
[Pic07]
4.Which of the following statements is
NOT true in terms of the free-radical
halogenation reactions of alkanes?
(a) Bromination has a better regioselectivity than chlorination
(b) Fluorine is more reactive than iodine.
(c) The reaction mechanism is a chain reaction.
(d) The initiation step is always endothermic.
(e) Brominations are faster than chlorinations.
5.The compound
[Pic08] has a formal charge of
(a) -1 on N (b) +2 on N (c)-1 on Al (d) +1 on Al (e) -1 on Br
6.Which of the following classification for the five species shown below is
the most appropriate?
1. H3O+ 2. HBr 3. Cl- 4. AlCl3 5. HO-
(a) 1,2,4 are electrophile when 3,5 are nucleophile.
(b) 1,2 are electrophile when 3,4,5 are nucleophile.
(c) 1,3,4 are electrophile when 2,5 are nucleophile.
(d) 1,4 are electrophile when 2,3,5 are nucleophile.
(e) 3,5 are electrophile when 1,2,4 are nucleophile.
7.How many of the following pairs of structures are depicting the same
compound?
1.
[Pic09] and
[Pic10] 2.
[Pic11] and
[Pic12] 3.
[Pic13] and
[Pic14]
4.
[Pic15] and
[Pic16] 5.
[Pic17] and
[Pic18]
(a) 1 (b) 2 (c) 3 (d) 4 (e) 5
8.
[Pic19]
The sum of all the digits that appear in the IUPAC name for this compound is
(a) five (b) six (c) seven (d) eight (e) nine
9.Which of the following statements is
LEAST likely to be true?
(a) The rotation barrier of ethane is 3.0 kcal/mol.
(b) The pKa of ethane is 30.
(c) The gauche butane interaction is 0.9 kcal/mol.
(d) The compound 2-methylbutane has twice as many secondary H's as tertiary
H's.
(e) In the chlorination of alkanes, 2-methylpropane will react faster than
butane.
10.Shown below are five comparisons of acid strengths. Which one of the
comparisons is
INCORRECT?
(a)
[Pic20] is more acidic than
[Pic21]
(b)
[Pic22] is more acidic than
[Pic23]
(c)
[Pic24] is more acidic than
[Pic25]
(d)
[Pic26] is more acidic than
[Pic27]
(e)
[Pic28] is more acidic than
[Pic29]
11.There are four different substituents, (1)-CN, (2)-CH=CH2, (3)-CH2NH2,
(4)CH2Br on an asymmetric carbon. Which choice is the correct priority for
determining the R/S configuration?
(a) (4)>(1)>(3)>(2) (b) (1)>(2)>(3)>(4) (c) (1)>(2)>(4)>(3)
(d) (4)>(2)>(1)>(3) (e) (2)>(3)>(1)>(4)
12.How many of the following compounds would be
CHIRAL?
1.
[Pic30] 2.
[Pic31] 3.
[Pic32] 4.
[Pic33] 5.
[Pic34] 6.
[Pic35]
(a) 2 (b) 3 (c) 4 (d) 5 (e) 6
B.简答题 (每大题十分,选七大题作答,共七十分)
The following table contains information you might need for answering the
questions in this section:
Table 1
Bond Dissociation Energy (kcal/mol)
──────────────────
CH3-CH3 88
C-H 1° 98
C-H 2° 95
C-H 3° 91
Sn-H 73
C-Cl 79
H-Cl 103
Cl-Cl 58
1.One chair conformation of cis-1-tert-butyl-2-methylcyclohexane is
significantly more stable than the other. (a) Draw the two chair
conformations of all the H atoms and substituents of this molecule and (b)
circle the most stable form.
2.Give an IUPAC name for Each of the following compounds. (a,b: 2%; c,d: 3%)
(a)
[Pic36] (b)
[Pic37] (c)
[Pic38] (d)
[Pic39]
3.(a) On the basis of Table 1, calculate the ΔG° value for the following
reaction at 25℃ with the assumption of ΔS° = 0 kcal/mol‧K and (b) draw a
reasonable mechanism for it.
[Pic40]
4.Considering the following radical H abstraction reactions,
(I)
[Pic41]
(II)
[Pic42]
draw a reaction-energy diagram, on the basis of Table 1, for both reactions
(I) and (II), which shows (a) their relative changes in activation energy
and enthalpy and (b) their relative positions of transition state that
conforms to the Hammond postulate. (c) Draw a reasonable structure for the
transition state of reaction (I).
5.For 2,3-dimethylbutane, show the conformations in 60° increments associated
with their correct relative energies on the diagram below. The Newman
projections have been started for you
[Pic43]. To complete each
conformation, draw in the remaining substituents on carbon 3 (C3) at the
back of each Newman projection. Rotate the C3 substituents
CLOCKWISE
relative to the stationary C2 carbon.
[Pic44] [Pic45]
6.(a) Formaldehyde (
[Pic46]) has a fairly large dipole moment of 2.33D, but
carbon monoxide (CO) has a small dipole moment of 0.11D. Use resonance and
electronegativity arguments to explain these results. (6%)
(b) Explain why the following equilibrium lies to the right:(4%)
[Pic47]
7.Consider the following structures A to D. Identify the following pairs of
molecules as enantiomers, diastereomers, or the same compound?
(a) A and B (b) A and C (c) A and D (d) B and C (E) B and D
(A)
[Pic48] (B)
[Pic49] (C)
[Pic50] (D)
[Pic51]
8.Cyclotheonamide A (see the structure below), isolated from marine sponges,
is a potent inhibitor of thrombin which plays a role in the clotting of
blood. (a)
CIRCLE ALL THE STEREOCENTERS and (b)
ASSIGN THE R/S
CONFIGURATIONS for those needed. (c) How many major types of functional
groups are present in this molecule?
[Pic52]
9.The guanidine functional group, part of the amino acid arginine and a key
functional group found in many proteins, is highly basic due to resonance
stabilization of its conjugate acid. Draw (a) the conjugate acid of
guanidine and (b) the resonance structures that show how the positive charge
is delocalized (Use curved arrows to indicate the flow of electrons.) (6%)
[Pic53]
(c) Convert the following structures to Fischer projection images. (4%)
[Pic54] [Pic55]
Over. Good Luck!
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