Chemistry 106 Fall 2006 Exam 1 Form A
1. Does this molecule have both cis and trans isomers?
Cl
A.
B.
C.
D.
E.
No, it has only the cis isomer.
Yes, this is the cis isomer.
Yes, this is the trans isomer.
No.
No, it has only the trans isomer
2. The attractive forces between hydrocarbons tend to be dominated by
A. London dispersion forces.
C. ion-ion interactions
E. hydrogen bonding.
B. dipole-dipole interactions.
D. ion-dipole interactions.
3. Name the compound
A. 4-octene
C. 5-heptene
E. 5-octene
B. 3-heptene
D. 3-octene
4. What is the systematic name of the following molecule?
A.
B.
C.
D.
E.
2,3-dipropyl-4,4,-dimethylpentane
2,2-dimethyl-3-sec-pentylhexane
1,1,4-trimethyl-3-propylheptane
4-tert-butyl-5-methylocatane
2,3-dipropyl-4,4-dimethylnonane
5. Which of the following is the chemical formula of pentane?
A. CH3CH2CH2CH2CH3
C. CH3CH3
E. CH3CH2CH2CH2CH2CH3
B. CH3CH2CH2CH3
D. CH3CHCHCHCH2
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Chemistry 106 Fall 2006 Exam 1 Form A
6. Pick the answer that has the correct names for both of the aromatic hydrocarbons shown
below.
A.
B.
C.
D.
E.
I. xylene
I. 1-ethyl-3, 4-dimethylbenzene
I. 1-ethyl-3,4-dimethylbenzene
I. 1,2-dimethyl-4-ethylbenzene
I. ethyldimethylbenzene
II. 1, 3, 4-trimethylbenzene
II. 1, 2, 4-trimethylbenzene
II. 1, 3, 4-trimethylbenzene
II. 1, 2, 4-trimethylbenzene
II. trimethylbenzene
7. Name this molecule. The black spheres represent C and the light grey spheres H.
A. cyclopentane
C. puckerane
E. cyclohexane (chair conformation)
B. cyclohexane (boat conformation)
D. dodecane
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Chemistry 106 Fall 2006 Exam 1 Form A
8. Amino acids are the building blocks from which organisms make proteins. Below is a Lewis
structure for the amino acid threonine. What organic functional groups does it contain?
CH 3
HCOH
H2N
A.
B.
C.
D.
E.
C
COH
H
O
alcohol
amine
carboxylic acid
b and c
a, b and c
9. The C-O-C bonding arrangement is called the __________ functional group
A. alcohol
E. carboxylic acid
B. amine
C. ether
D. ester
10. Which of the following is true about normal alkanes?
A.
B.
C.
D.
E.
They all contain carbon, hydrogen, and oxygen in consistent ratios.
Some are gases, some are liquids, and some are solids at room temperature.
They all exhibit strong hydrogen bonding with one another and with water.
They all make good lubricants.
Some are yellow, some are red, and some are blue, depending on the chain length.
11. A pot of water is heated with 10 J of heat at constant pressure. What is the enthalpy
change (ΔH) for this process?
A. 15 J
D. -5 J
B. 5 J
E. 10 J
C. -10 J
12. Indicate which of the following bonds will require the most energy to dissociate.
A.
B.
C.
D.
E.
C=N
C-N
they are all the same.
there are no trends, so cannot tell without measuring.
C≡N
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Chemistry 106 Fall 2006 Exam 1 Form A
13. For which of the following processes will ΔH be much less than ΔE?
A.
B.
C.
D.
E. ΔH is much less than ΔE in all cases.
14. Use average bond enthalpies to determine the amount of energy released when 250 g of
propane (CH3CH2CH3) gas are burned. The combustion reaction is
CH3CH2CH3 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (g).
SOME AVERAGE BOND ENERGIES ARE LISTED BELOW
Bond Energy kJ/mol
Bond Energy kJ/mol
C-C
348
C=C
612
C-O
360
C=O
743
C-H
413
O-O
146
O=O
497
O-H
463
A. -1.7 × 103 kJ
E. 992 kJ
B. -7.2 × 105 kJ
C. -2.7 X 103 kJ
D. -9.5 × 103 kJ
15. A student dissolving some ammonium nitrate (NH4NO3) in water notices that the beaker
cools as the solid dissolves. This is an example of a(n) __________.
A. refrigeration
C. exothermic process
E. thermodynamic cycle
B. combustion reaction
D. endothermic process
16. If a book falls off a table, what type of energy does the book possess while it is falling?
A. kinetic energy only
C. potential and kinetic energy
E. potential energy only
B. thermal and potential energy
D. radiant and kinetic energy
Page 4
Chemistry 106 Fall 2006 Exam 1 Form A
17. Indicate which of the following compounds is most stable relative to its elements.
A. H2Se (g), ΔHf0 = 29.7 kJ/mol
C. O3 (g), ΔHf0 = 142.3 kJ/mol
E. NH3(g), ΔHf0 =-46.1 kJ/mol
B. SO2 (g), ΔHf0 = -269.9 kJ/mol
D. PbBr2 (s), ΔHf0 = -277.4 kJ/mol
18. If the enthalpy change in a system is positive, then
A.
B.
C.
D.
E.
the total enthalpy of the universe increases.
heat is lost by the system.
the total energy of the universe decreases.
the enthalpy change in the surroundings is positive.
the enthalpy change in the surroundings is negative.
19. Given the enthalpies of formation for the following substances, determine ΔHrxn for
Cl2 (g) + C2H2Cl2 (g) + 2 O2(g)→ 2 CO2(g) + 4 HCl (g).
Substance
Cl2
C2H2Cl2
HCl
CO2
A. 1160.5 kJ/mol
D. -490.1 kJ/mol
ΔHf0 (kJ/mol)
0
4.27
-92.3
-393.5
B. -1160.5 kJ/mol
E. -1151.9 kJ/mol
C. 490.1 kJ/mol
20. Use the following reactions to determine ΔHrxn for the reaction of ethylene (C2H4) with
chlorine (Cl2):
H2 (g) + Cl2 (g) → 2HCl (g); ΔH = -92.30 kJ
C (s) + 2Cl2 (g) → CCl4 (g); ΔH = -106.7 kJ
2C (s) + 2H2 (g) → C2H4 (g); ΔH = 52.3 kJ
C2H4 (g) + 6Cl2 (g) → 2CCl4 (g) + 4HCl (g); ΔH = ?
A. -146.7 kJ
D. 350.0 kJ
B. -223.7 kJ
E. -450.3 kJ
C. -398.0 kJ
21. How much work is done on a gas when it is compressed by a constant pressure of 0.500 atm
from a volume of 550.00 mL to a volume of 50.00 mL?
A. -0.279 J
C. 279 J
E. 0.253 J
B. 25.3 J
D. -25.3 J
Page 5
Chemistry 106 Fall 2006 Exam 1 Form A
22. During a calorimetry experiment, a positive change in temperature corresponds to
A.
B.
C.
D.
E.
an endothermic reaction.
an exothermic reaction.
heat transfer from the calorimeter.
the enthalpy of formation of the compound being studied.
none of the above.
23. The heating curves for four different liquids are shown below. Which of the substances has
the greatest molar heat capacity?
A. V
B. III
C. II
D. I
E. IV
24. What is the heat capacity of a calorimeter if the temperature of the calorimeter rises by
5.678ºC when 0.750 g of benzoic acid was combusted (benzoic acid produces 26.38 kJ of
heat when one gram is combusted).
A. 6.20 kJ/ºC
C. 4.65 kJ/ºC
E. 1112 kJ/ºC
B. -3.57 kJ/ºC
D. 3.49 kJ/ºC
25. Which of the following objects will warm the slowest, assuming you supply heat energy at
10.0 J/s and have equal grams of each?
A.
B.
C.
D.
E.
A container of water (cp = 75.3 J/K mol)
An iron skillet (cp = 25.1 J/K mol)
They will all warm at the same rate.
A copper pot (cp = 24.4 J/K mol)
An aluminum pan (cp = 24.3 J/K mol)
26. What will be the final temperature of a 10.0 g piece of iron (cp = 25.09 J/K mol), initially at
25ºC, if it is supplied with 9.5 J from a stove?
A. 101ºC
B. 23ºC
C. 1,356ºC
Page 6
D. 25ºC
E. 27ºC
Chemistry 106 Fall 2006 Exam 1 Form A
27. A fuel value is
A.
B.
C.
D.
E.
the energy released when on mole of CO2 is released.
the energy released when one gram of a substance is formed (kJ/g).
the amount of energy contained in one mole of a substance (kJ/mol).
the energy released when one gram of a substance is burned (kJ/g).
the cost of energy in kJ/$.
28. The function of gasoline additives like ethanol are
A.
B.
C.
D.
E.
to decrease octane rating.
to make it less volatile.
to promote complete combustion.
to decrease odor.
none of the above
29. The enthalpy of combustion of sucrose (C12H22O11) is -5643 kJ/mol. What is the fuel value
of sucrose?
B. 16.48 kJ/g
A. 2.921 × 10-3 kJ/g
C. 46.40 kJ/g
D. 1.932 × 106 kJ/g
E. 6.061 x 10-2 kJ/g
30. The fraction of crude oil that is used for gasoline consists primarily of normal alkanes.
Refineries spend extra money to convert some of these normal alkanes to branched alkanes
(raise the octane rating). Why?
A.
B.
C.
D.
E.
to make the fuel easier to ignite.
to make the fuel harder to ignite.
to increase the energy content of the fuel.
to make the fuel smell better.
to decrease the energy content of the fuel.
31. Storage of hydrogen for use as a fuel is made difficult by
A.
B.
C.
D.
E.
its corrosive nature.
its tendency to undergo nuclear fusion.
its tendency to make storage tanks float away.
its high density
its extremely low boiling point.
32. As plant tissue is converted to coal by heat and pressure deep underground H and O are lost
from the material. Thus older coal usually
A.
B.
C.
D.
E.
contains fewer aromatic rings.
is lower in energy content.
is higher in energy content.
is softer.
is diamond like.
Page 7
Chemistry 106 Fall 2006 Exam 1 Form A
33. Rank the following according to their fuel values in order of decreasing energy/mass.
C8H14, CO, CH3OH, CH3CH2OCH3
A.
B.
C.
D.
E.
C8H14> CH3CH2OCH3 > CH3OH > CO
CO > CH3OH > CH3CH2OCH3 > C8H14
CH3CH2OCH3 > CO > CH3OH > C8H14
C8H14 > CO > CH3OH > CH3CH2OCH3
CO > CH3CH2OCH3 > CH3OH > C8H14
34. In fractional distillation of an ideal solution, which component is enriched in the vapor phase?
A.
B.
C.
D.
E.
the component originally in deficit
the component originally in excess
the composition is the same as the liquid phase
the component with the lower vapor pressure, Pº
the component with the higher vapor pressure, Pº
35. A polysaccharide is formed from monosaccharides
A.
B.
C.
D.
E.
through the hydrolysis process.
by the addition of water molecules at each coupling site.
that are in their straight-chain form.
by their reaction to a polymerase.
through condensation of C-1 and C-4 hydroxyls on adjacent units.
36. In the sketch of the fructose molecule, what organic functional groups are observed?
HOCH2
A.
B.
C.
D.
E.
H
H
OH
C
C
C
C
OH OH H
O
CH2OH
aldehyde and alcohol groups
ketone and alcohol groups
alcohol groups
aldehyde groups
alcohol and carboxylic acid groups
37. The cyclization reaction of fructose is different from that of glucose because
A.
B.
C.
D.
E.
the cyclization reaction forms a ketone.
instead of a six-membered ring a five-membered ring is formed.
water is released
the orientation of the cyclization is backward.
the aldehyde group migrates to a new position.
Page 8
Chemistry 106 Fall 2006 Exam 1 Form A
38. What difference(s) is (are) there in an α-glycosidic bond and a β-glycosidic bond?
A. Humans can digest α-glycosidic bonds but not β-glycosidic bonds.
B. α-glycosidic bonds occur in starch and β-glycosidic bonds occur in cellulose.
C. α-glycosidic bonds involve condensation of α-glucose units via C-1 hydroxyl group of
one glucose and C-4 hydroxyl group of another. β-glycosidic bonds link β-glucose
units in a similar fashion.
D. all the above
E. none of the above
39. A 10.00 g sample of a hydrocarbon (that is, a compound that contains carbon and hydrogen
only) is burned in oxygen and the carbon dioxide and water produced carefully collected and
weighed. The mass of the carbon dioxide was 30.50 grams, and the mass of the water was
14.98 grams. What was the emprical formula of the hydrocarbon?
A. C2H6
B. C6H7
C. C5H12
D. C1H6
E. C5H6
40. Combustion analysis of an organic compound to determine the percentages of carbon,
hydrogen, and oxygen in the formula depends on the following assumption(s):
A.
B.
C.
D.
E.
the mass of the resulting carbon dioxide is equal to the mass of the carbon in the sample.
the compound burns completely to form carbon dioxide and water.
all the oxygen in the products comes from the added oxygen gas.
all the above
none of the above
Page 9
Answer Key for Test “Exam 1 F06 Form A”, 9/19/07
No. in No. on
Q-Bank Test Correct Answer
12 121
11 20
12 100
12 112
11 21
12 113
12 25
12 118
12 44
12 19
11 42
11 105
11 45
11 64
11 30
11 11
11 81
11 102
11 106
11 97
11 101
11 75
11 50
11 68
11 103
11 52
11 88
12 41
11 89
12 111
12 85
12 120
12 115
12 10
12 64
12 116
12 61
12 70
12 95
12 93
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
C
A
D
D
A
B
E
E
C
B
E
E
B
D
D
C
D
E
B
E
B
B
A
D
A
E
D
C
B
B
E
C
A
E
E
B
B
D
C
B
Page 1