Download 1 Sample Paper for Chem 1008 (Final Exam) Part I. Multiple

Sample Paper for Chem 1008 (Final Exam)
Part I. Multiple Choices
(2 points each; 50 points in total)
1. Which one of the following compounds has the greatest melting point?
(a) Cl2
(b) Br2
(c) ICl
(d) IBr
2. Arrange the following in order of increasing boiling point: RbF, CO2, CH3OH, CH3Br
(a) RbF < CO2 < CH3OH < CH3Br
(b) CO2 < CH3OH < CH3Br < RbF
(c) CO2 < CH3Br < CH3OH < RbF
(d) CH3OH < CH3Br < RbF < CO2
3. Place the following liquids at –50 0C in order of increasing vapor pressure: dimethyl ether,
ethanol, and propane.
(a) dimethyl ether < ethanol < propane
(b) propane < dimethyl ether < ethanol
(c) ethanol < propane < dimethyl ether
(d) ethanol < dimethyl ether < propane
4. In salts of formula MX, the coordination numbers of M and X.
(a) must be equal
(b) can be different and can be the same
(c) are always different
(d) none of the above
5. For the hcp and fcc close-packing arrangements, the coordination numbers are,
respectively,
(a) 6 and 8
(b) 8 and 10 (c) 10 and 12 (d) 12 and 12
6. The number of tetrahedral holes in an fcc unit cell is.
(a) 12
(b) 4
(c) 6
(d) 8
7. For an fcc close packing arrangement,
(a) only one (b) only two (c) many
one can choose
(d) only four
type(s) of unit cells.
8. Which of the following reactions belong to the acid-base reactions?
(a) H + OH H2O.
(b) PF3 + F2 PF5.
(c) SiF4 + 2NaF Na2[SiF6].
(d) Mo + 6CO Mo(CO)6.
9. Select the weakest Bronsted acid.
(a) H3PO4
(b) H2CO3
(c) H3BO3
(d) H2SeO4
10. Which of the following pairs is the stronger acid?
H2S2O3 vs. H2SO4
[Co(H2O)6]3+ vs. [Co(H2O)6]2+
11. Which of the following compounds can act as both hard and soft bases?
(a) dimethylsulfoxide
(b) [S2O3]2- (c) [NO3](d) [CO3]21
12. Which of the following statements is correct?
(a) A Lewis base is an electron-pair acceptor and acts as a nucleophile.
(b) A Lewis base is an electron-pair acceptor and acts as an electrophile.
(c) A Lewis base is an electron-pair donor and acts as an electrophile.
(d) A Lewis base is an electron-pair donor and acts as a nucleophile.
(e) A Lewis base is the same as a Brønsted-Lowry acid.
13. Which of the following statements is not true?
a) CH3CH2C(O)NH2 has a higher boiling point than CH3CH2C(O)NHCH3.
b) CH3CH2CH(NH2)CH2COOH is more soluble in water than
CH3CH2CH(NH2)CH2C(O)OCH3.
c) CH3CH2COOH has a higher boiling point than CH3CH2C(O)NH2.
d) HO2CCH2CH2CO2H has a higher boiling point than CH2CH2CH2OH.
14. Shown in the right diagram is the structure of morphine.
Which of the following collections of functional groups are present?
(a) primary-alcohol, secondary-amine, ether and ketone
(b) tertiary-alcohol, secondary-amine, ether and phenol
(c) secondary-alcohol, tertiary-amine, ether and phenol
(d) secondary-alcohol, primary amine, phenol and aldehyde
(e) secondary-alcohol, tertiary-amine, phenol and amide
15. Which of the following polymers is expected to be the softest?
H Cl
H
Cl
H
Cl
H
Cl
C C
C
C
C
C
C
C
C
n
H
n
H
C
O
O
OCH3
OCH2CH2OH
(a)
(b)
n
H
C
O
CH3
(c)
n
H
C
O
OCH2CH3
(d)
16. The base sequence of one strand of a piece of double-stranded DNA is found to be
-TGTCA-. The sequence of the other strand is:
(a) -TGACA-
(b) -ACAGT-
(c) -TGTCA-
(d) -GTCAC-
17. The closer together in size a cation and an anion, the more likely the cation is to
reside in a
(a) cubic hole
(b) tetrahedral hole
(c) octahedral hole
(d) square hole
18. Lubricating oil (lubricants or greases) are hydrocarbons
(a) having higher numbers of carbon atoms in the compounds.
(b) having smaller numbers of carbon atoms in the compounds.
(c) containing both higher and smaller numbers of carbon atoms in the compounds.
(d) none of above.
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19. The segment –CH2CH2CH2CH2CH2CH2- represents the polymer named:
(a) polybutylene
(b) polyhexene
(c) polypropene
(d) polyethylene
20. Nucleic acids contains
(a) protein units
(b) polyamide units
(c) sugar units
21. In the fructose molecule, the
-member-ring contains
oxygen(s).
(a) 5, 4, 1
(b) 6, 5, 1
(c) 6, 4, 2
(d) 5, 3, 2
(d) none of above
carbons and
22. Select the correct statements.
(a) Human can digest any monsaccharides.
(b) Human can metabolize cellulose.
(c) Human can digest any polysaccharides.
(d) Human can digest disaccharides having α-linkages.
23. Which of the following are relevant to carbohydrates
(a) Teflon
(b) sugar
(c) starch
(d) amino acids
24. What is the correct shorthand notation for the voltaic cell that utilizes the reaction below.
Fe(s) + Cu2+(aq) → Fe2+(aq) + Cu(s)
(a)
(b)
(c)
(d)
(e)
Fe(s) | Fe2+(aq) || Cu2+(aq) | Cu(s)
Cu(s) | Cu2+(aq) || Fe2+(aq) | Fe(s)
Fe(s) | Cu2+(aq) || Fe2+(aq) | Cu(s)
Pt(s) | Fe2+(aq) || Cu2+(aq) | Pt(s)
Fe2+(aq) | Fe(s) || Cu(s) | Cu2+(aq)
25. The following two half-reactions are involved in a galvanic cell. At standard conditions,
what species are produced at each electrode?
Ag+(aq) + e− → Ag(s)
+0.80 V
Ni2+(aq) + 2e− → Ni(s)
−0.23 V
(a) Ag(s) is produced at the cathode and Ni2+(aq) is produced at the anode.
(b) Ag(s) is produced at the cathode and Ni(s) is produced at the anode.
(c) Ag+(aq) is produced at the anode and Ni(s) is produced at the cathode.
(d) Ag+(aq) is produced at the anode and Ni2+(aq) is produced at the cathode.
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Part II. Medium and Long Questions
1. (a) Please give the structures of D and E. (4 points)
D
E
(b) Rank the following compounds in order of increasing boiling points. (4 points)
C4H9OH
CH3COOCH3
CH3CH2CH2COONa
C5H12
CH3CH2COOH
2. (a) Please draw the structural forms of α-glucose and β-glucose. (5 points)
(b) Briefly describe the structural difference between starch and cellulose. (5 points)
3. Aluminum sulfide, Al2S3, gives off a foul odor characteristic of hydrogen sulfide when it
becomes damp. Write a balanced chemical equation for the reaction and discuss it in terms of
hard/soft acid-base concepts.
(5 points)
4. A rhenium oxide structure is cubic with Re at each corner of the unit cell and one O atom
on each unit cell edge midway between the Re atoms.
(1) Sketch this unit cell.
(4 points)
(2) Determine the molecular formulae for the solid.
(2 points)
(3) Determine the coordination numbers for Re and O.
(4 points)
5. Both H5IO6 and HClO3 are oxoacids. Based on their Lewis structures, please
determine and explain briefly which one has higher acidity.
(5 points)
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6. A voltaic cell is based on the following two half-reactions: (5 points)
Ni+2(aq) + 2e- → Ni(s) E° = -0.25 V
Cr+3(aq) + 3e- → Cr(s) E° = -0.74 V
Complete the following sentences/questions.
a. Cr serves as the
(cathode/anode).
b. The direction of electron flow through the external wire is from the
to the
(Ni/Cr) electrode.
c. Anions in solution will migrate toward the
(Ni/Cr)
(Ni+2/Ni or Cr3+/Cr) electrode.
d. The net cell reaction is:
e. E°(cell) =
V
7. Write the following sugars in an open-chain form (in a Fischer projection) by adding the
missing H and OH groups. (5 points)
Note: that an –OH group on the right in a Fischer projection is on the bottom face of the
pyranose ring, and an –OH group on the left in a Fischer projection is on the top face of the
ring.
END
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Answer Keys:
Part I. Multiple Choices
(1) (d)
(2) (c)
(6) (d)
(7) (c)
(11) (a), (b)
(12) (d)
(16) (b)
(17) (a)
(21) (a), (b)
(22) (a), (d)
(3) (d)
(8) (c), (d)
(13) (c)
(18) (a)
(23) (b), (c)
(4) (a)
(9) (c)
(14) (c)
(19) (d)
(24) (a)
(5) (d)
(10) H2SO4; [Co(H2O)6]3+
(15) (a)
(20) (c)
(25) (a)
Note: In order not to confuse students, in the coming final exam, one answer per question
will be adopted in the section of multiple choice questions.
Part II. Medium and Long Questions
1. (a)
Br
CH3
D
E
(b)
Pentane
Methyl acetate
Butyl alcohol
Propionic acid
Sodium butanoate
Br
2. (a)
CH2OH
CH2OH
O
H
H
O
H
H
H
OH
OH
OH
H
OH
H
OH
OH
α-glucose
OH
H
H
H
OH
β-glucose
(b) Starch is polymer of α-glucose: condensation of α-glucose through α-linkages.
Cellulose is polymer of β-glucose: condensation of β-glucose through β-linkages.
3. Al2S3 + 3H2O 3 H2S (gas) + Al2O3
Al3+ is a hard Lewis acid while S2- is a soft one. Therefore, Al2S3 is not very stable. When
Al2S3 reacts with an O-donor (a hard Lewis base), Al3+ forms more stable compound with O2according to the Hard/Soft Acids/Bases Principle.
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4. (a)
Re
O
Re
O
O
Re
O
Re
O
O
O
O
Re
O
O
Re
O
Re
O
Re
(b) ReO3
(c) The coordination number for Re is 6 and for O is 2.
5.
O
HO
HO
O
OH
OH
I
Cl
O
OH
OH
HClO3 has two oxo groups in the Lewis structure while H6IO5 has only one. Therefore,
HClO3 is expected to be more acidic.
6. See the answer keys for the 2nd assignment which will be given later.
7. a)
HO
H
H
b)
H
OH
OH
HO
H
c)
H
OH
H
H
HO
OH
OH
H
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