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Chem 101B Study Questions
Chapters 19,21,22
Review Thursday 5/4/2017
Final Exam 12:30 p.m., Tuesday 5/9/2017
Not collected for credit.
1. Identify the missing particle in the following equation:
238
4
92 U  2 He + ?
234
A) 90
Th
B)
234
92
U
C)
242
94
Pu
D)
242
90
E)
Th
none of these
2. An unstable isotope of rhenium, 191Re, has a half-life of 9.8 minutes and is a beta
producer. What is the other product of the reaction?
A) 191W
B) 192Pt
C) 190Os
D) 191Os
E) 190W
3. It is desired to determine the concentration of arsenic in a lake sediment sample by
75
means of neutron activation analysis. The nuclide 33
As captures a neutron to form
76
33
As , which in turn undergoes  decay. The daughter nuclide produces the
characteristic  rays used for the analysis. What is the daughter nuclide?
76
A) 34
Se
74
B) 34 Se
C)
76
32
Ge
D)
74
31
Ga
E)
75
34
Se
Page 1
4. Electron capture transforms
40
A) 19
K–
B)
39
20
Ca
C)
40
20
Ca
D)
40
18
Ar
E)
4
2
40
19
K into what nuclide?
He
214
5. If 82
Pb undergoes a beta decay and the product of this decay undergoes another beta
decay, which nuclide is produced?
214
A) 82
Pb
206
B) 82 Pb
C)
212
82
Bi
D)
214
84
Po
E)
212
83
Bi
6. In the following fission reaction, identify the other product:
235
1
139
1
92 U + 0 n  53 I + 2 0 n + __________
A) 95
40 Zr
B)
95
42
Mo
C)
94
42
Mo
D)
89
39
Y
E)
95
39
Y
7. Iron-56 is a stable nuclide. What is the most likely decay for the iron-59 isotope?
A) -ray emission
B)  decay
C) two of these
D)  decay
E) positron emission
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8. Nuclides with too many neutrons to be in the band of stability are most likely to decay
by what mode?
A) beta emission
B) positron production
C) alpha emission
D) fission
E) electron capture
Use the following to answer questions 9-10:
The U-238 nucleus decays to form Pb-206 by  and  decays.
9. Calculate the number of  decays.
A) 6
B) 8
C) 4
D) 2
E) none of these
10. Calculate the number of  decays.
A) 4
B) 8
C) 2
D) 6
E) none of these
11. The rate constant for the beta decay of thorium-234 is 2.883  10–2 / day. What is the
half-life of this nuclide?
A) 1.217 days
B) 0.693 days
C) 96.15 days
D) 48.07 days
E) 24.04 days
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12. The number of a certain radioactive nuclide present in a sample decays from 160. to 20.
in 40 minutes. What is the half-life of this radioactive species?
A) 28 minutes
B) 8 minutes
C) 23 minutes
D) 13 minutes
E) 18 minutes
13. The number of half-lives needed for a radioactive element to decay to about 6% of its
original activity is (choose nearest number):
A) 3
B) 4
C) 6
D) 2
E) 5
14. The I-131 nuclide has a half-life of 8.0 days. If you originally have a 1.8-kg sample,
after 1.0 months you will have approximately
A) 201 g
B) 134 g
C) 149 g
D) less than 1 g
E) 268 g
15. If more than one neutron from each fission event causes another fission event, the
fission situation is described as
A) supercritical
B) moderated
C) subcritical
D) critical
E) none of these
16. What component of a nuclear reactor moderates the rate of the reaction?
A) cyclotron
B) steam turbine
C) control rods
D) cooling water
E) containment shell
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17. The greatest radiation exposure for Americans comes from which of the following?
A) electrical transmission wires
B) a combination of the natural causes of radiation including cosmic rays
C) nuclear power plants
D) medical x-rays
E) industrial waste
18. Which type of radiation has the lowest penetrating ability?
A) beta particle
B) alpha particle
C) positron
D) gamma ray
E) more than one of these
19. Which of the following is a d7 ion (contains 7 d electrons)?
A) Mn(IV)
B) Co(II)
C) Cu(II)
D) Mn(II)
E) At least two of the above (a-d) are d7 ions.
20. What is the electron configuration of the Mn(II) ion?
A) [Ar] 3d5
B) [Ar] 4s23d5
C) [Ar] 4s13d5
D) [Ar] 4s23d3
E) none of these
21. The electron configuration for Cr2+ is
A) [Ar] 4s13d5
B) [Ar] 3d4
C) [Ar] 4s23d2
D) [Ar] 4s23d4
E) none of these
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22. A complex ion is a charged species consisting of a metal ion surrounded by
A) ligands
B) ligands and counter ions
C) hydrogen ions
D) other transition metals
E) none of these
23. Which of the following is true?
A) The third ionization energy for Zn is significantly lower than that of Sc.
B) The first ionization energy for Zn is significantly higher than that of Sc.
C) The first ionization energy for Zn is significantly lower than that of Sc.
D) The third ionization energy for Zn is significantly higher than that of Sc.
E) Two of these are correct.
24. The metals with the highest ionization energies are most likely to be found in nature in
the elemental state.
A) True
B) False
25. An element that is a significant component of both brass and bronze is:
A) iron
B) copper
C) nickel
D) zinc
E) tin
26. Which of the following complexes can exhibit optical isomerism?
(en = H2NCH2CH2NH2 and is a bidentate ligand)
A) Co(NH3)3Cl3
B) cis–Co(en)2Cl2
C) cis–Co(NH3)4Cl2
D) trans–Co(en)2Br2
E) none of these
27. Which of the following complexes shows geometrical isomerism?
A) [Co(NH3)5Cl]Cl2
B) [Co(NH3)5Cl]SO4
C) K[Co(NH3)2Cl4]
D) [Co(NH3)6]Cl3
E) none of these
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28. Which complex ion shape is not capable of showing cis–trans isomerism?
A) square planar
B) tetrahedral
C) octahedral
D) two of these
E) none of these
29. Which of the following is true about coordination complexes?
A) Only complexes with coordination number six are found in nature.
B) When the ligands approach a transition metal ion in an octahedral field, the dxz, dyz,
and dxy atomic orbitals are affected the least by the ligands.
C) The metal is a Lewis base and the ligands are Lewis acids.
D) None of the above is true.
E) All of the above are true.
Use the following to answer questions 30-31:
Specify the number of unpaired electrons.
30. CuCl2– (linear)
A) 5
B) 2
C) 4
D) 0
E) 1
31. NiCl42– (tetrahedral)
A) 5
B) 0
C) 1
D) 2
E) 4
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32. Which of the following crystal field diagrams is correct for Co(CN)64– where CN– is a
strong field ligand?
A)
B)
C)
D)
E)
none of these
33. True or False? The complexes of Zn2+ are all diamagnetic.
A) True
B) False
Use the following to answer questions 34-35:
How many unpaired electrons are found in each of the following complex ions?
34. NiCl42–
35. [Ni(CN)6]4–
36. The color of a transition metal complex results from:
A) transition of an electron between d orbitals
B) bending vibrations
C) transition of an electron between an s and a p orbital
D) nuclear magnetic resonance
E) stretching vibrations
Page 8
37. Name the following:
CH3
CH3CH2CCH3
CH2CH3
A)
B)
C)
D)
E)
2-methyl-2-ethylbutane
2,2-diethylpropane
n-heptane
3,3-dimethylpentane
none of these
38. How many isomers of C3H8 are there?
A) 6
B) 3
C) 5
D) 1
E) 2
39. In lecture, the professor named a molecule 4-ethylpentane. An alert student pointed out
that although the correct structure could be drawn, the name did not follow systematic
rules. What is the correct systematic name for the molecule?
A) 3-methylhexane
B) 4-methylhexane
C) 1-methyl-1-propylpropane
D) 2-ethylpentane
E) none of these
40. Hydrocarbons containing a carbon–carbon triple bond are called
A) alkanes
B) alkynes
C) aldehydes
D) alkenes
E) cyclic alkanes
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41. Name the following:
CH2CH3
CH3 C
A)
B)
C)
D)
E)
C
C
H
H
2-ethyl-3-butyne
1-hexyne
3-methyl-1-pentyne
3-methyl-4-pentyne
2-ethynyl butane
42. Name the following:
Cl
CH3
H3C
Cl
A) 2,3-dichloro-trans-2-butene
B) 1-chloro-1-methyl-2-chloro-propene
C) 2,3-dichloro-cis-2-butene
D) 2,3-dichloro-1-methyl-propene
E) 2-chloro-3-chloro-cis-2-butene
43. Name the following:
CH3(CH2)4 CH3
A) butane
B) pentane
C) heptane
D) ethane
E) hexane
Page 10
44. Which of the following compounds can exhibit geometric isomerism?
A)
Cl
H
C
C
Cl
H
B)
H3 C
CH3
C
C
H3 C
CH2Cl
C)
Br
H
C
C
Cl
H
H
H
D)
C
Cl
C
Cl
E)
H
H
H
C
C
H
Cl Cl
45. What is the compound represented by the following structure?
A)
B)
C)
D)
E)
benzene, C6H6
cyclohexatriene, C6H12
cyclohexene, C6H10
cyclohexatriene, C6H9
cyclohexane, C6H12
46. The boiling point of methanol is much higher than that of ethane. This is primarily due
to
A) the significant molecular size difference between methanol and ethane
B) the carbon oxygen double bond in the methanol
C) the hydrogen bonding in methanol
D) the difference in molar masses of methanol and ethane
E) none of these
Page 11
47. Classify the following molecule:
CH3 H
H3C
C
C
O
H
CH2
CH3
H
A)
B)
C)
D)
E)
tertiary alcohol
primary alcohol
phenol
secondary alcohol
ether
48. Which molecule is an ether?
A) CH3CH2NH2
B)
O
CH3CH2 COCH3
C) CH3CH2OCH3
D)
O
E)
CH3CH2 CCH3
none of these
49. Identify the type of organic compound shown:
H3C C CH2CH3
O
A)
B)
C)
D)
E)
ester
amine
alcohol
aldehyde
none of these
Page 12
50. Identify the type of organic compound shown:
H H
H C C C O
H H H
A)
B)
C)
D)
E)
ester
amine
ketone
aldehyde
none of these
51. What organic compounds often have pleasant fruity odors?
A) carboxylic acids
B) ethers
C) amines
D) alkynes
E) esters
52. Referring to the structures below, which statement is true?
O
I.
II.
H C O CH2 CH2OH
O
HOCH2CH2
III.
A)
B)
C)
D)
E)
C
OH
O
HOCH2CH2 O C H
I and III are structural isomers of each other.
II and III are different conformations of the same compound.
I and II have different molecular formulas.
I and III are the same compound.
II and III are stereoisomers of each other.
53. Which molecule is an ester?
A) CH3CH2NH2
B)
O
CH3CH2 COCH3
C) CH3CH2OCH3
D)
O
E)
CH3CH2 CCH3
none of these
Page 13
54. Which of the following functional groups does not contain a doubly bonded oxygen
(C=O)?
A) Carboxylic acid.
B) Aldehyde.
C) All contain a C=O double bond.
D) Ketone.
E) Carboxyl.
55. Identify the type of organic compound shown: (CH3)3N
A) ester
B) ketone
C) aldehyde
D) amine
E) none of these
56. Why does octane have a higher boiling point than ethane, 126°C versus –89°C?
A) Octane has stronger London dispersion forces than ethane.
B) Octane exhibits hydrogen bonding and ethane does not.
C) Octane has a higher vapor pressure than ethane.
D) Octane contains more double bonds than ethane.
E) At least two of the above are correct.
-------------57. Consider a certain type of nucleus that has a half-life of 32 min. Calculate the percent of
original sample of nuclides remaining after 2.6 hours have passed.
58. The half-life of 90 Sr is 28 years. How long will it take for a given sample of
83 % decomposed?
59. The rate constant for the decay of
45
20
45
20
90
Sr to be
Ca is 4.230  10–3 / day. What is the half-life of
Ca ?
60. The half-life of a sample has been defined as the time it takes for half of a sample to
decay. The fifth-life can be defined as the time it takes for one-fifth of a sample to
decay. Given these definitions, calculate the fifth-life of a sample that has a half-life of
28 years. (hint: consider fifth life means that N = 0.8No)
Page 14
61. The half-life for electron capture for
original
40
19
40
19
K is 1.30  109 years. What percent of the
K remains after 3.21  109 years?
62. Calculate the change in energy released (kJ/mol) for the decay of Radium-226 given the
following data:
226
4
222
+
 
88 Ra
2 He
86 Rn
226.0254 g/mol
4.0026 g/mol
222.0176 g/mol
–13
63. Iron-56 ( 56
J).
26 Fe) has a binding energy per nucleon of 8.79 MeV. (1MeV is 1.60  10
Determine the difference in mass between one mole of iron-56 nuclei and the
component nucleons of which it is made.
64. Calculate the binding energy of a Ni-60 atom (in MeV/nucleon).
1 amu = 1.660539×10-27 kg
1 MeV = 1.60218×10-13 J
mass 60Ni atom = 59.930789 amu
mass proton = 1.007276 amu
mass neutron = 1.008665 amu
65. Which of the following compounds exhibit geometric isomers?
I. Pt(NH3)2Cl2 (square planar)
II. [Co(H2O)2]Cl3
III. Ni(NH3)4(NO2)2
IV. K2[CoCl4]
66. Explain why copper(I) complexes would be expected to be colorless.
67. Fluoride ion ranks low in the spectrochemical series and produces a weak crystal field in
complex ions. Based on this information, predict the number of unpaired electrons in
CoF64–.
68. A d6 ion (Fe2+) is complexed with six strong-field ligands (for example, SCN–). What is
the number of unpaired electrons in this complex?
Page 15
69. The complex ion NiCl42– is tetrahedral. The number of unpaired electrons in the
complex is:
Use the following to answer questions 70-71:
Draw the orbital-splitting diagram for the species below.
70. [Fe(H2O)6]3+ (assume weak field)
71. K4Mn(CN)6 (assume strong field)
72. Name the compound with carbon skeleton (minus any hydrogen atoms) below:
C
C
C C
C C
C C
C C
C
C C
73. Name the following compound:
H H H
H
C
C
C
H
OH H
H
74. Provide and name three (3) isomers of hexane.
75. What is the product of the following reaction?
CH3CH=CHCH2CH3 + Cl2 → ??
76. Provide the structure of 3-methyl-1-butanol.
77. Provide the structure of trans-2-hexene.
78. Provide the structure of 4-decyne.
Page 16
Answer Key
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.
41.
42.
43.
A
D
A
D
D
E
B
A
B
D
E
D
B
B
A
C
B
B
B
A
B
A
D
A
B
B
C
B
B
D
D
C
A
0
2
A
D
D
A
B
C
A
E
Page 17
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
D
A
C
A
C
E
D
E
D
B
C
D
A
3.4%
72 years
163.8 days
9.0 years
18.1%
4.7  108 kJ/mol
5.27  10–4 kg
mass defect = –0.550229 amu
mass defect = –9.136774e–28 kg
binding energy = 8.211723e–11 J/60Ni or 512.53 MeV
binding energy per nucleon = 8.5422 MeV/nucleon
65. I, III exhibit geometric isomers.
66.
67.
68.
69.
70.
Others do not:
II--Linear can't do this
IV--since Cl− ligands are all the same
Copper (I) has lost 1 valence electron, so the d-electron configuration is d10. Even in a
crystal field, there would be no vacant higher energy d orbitals for an electron to absorb
a photon. Thus no visible wavelengths of light would absorbed.
3
0
2
E↑
71.
E↑
72. 4-ethyl-2,5,6-trimethyloctane
73. 2-propanol (common name: isopropyl alcohol)
Page 18
74. There are 5 total isomers of hexane:
hexane, CH3(CH2)4CH3
2-methylpentane, (CH3)2CHCH2CH2CH3
3-methylpentane, (CH3CH2)2CHCH3
2,3-dimethylbutane, (CH3)2CHCH(CH3)2
2,2-dimethylbutane, (CH3)3CCH2CH3
75. CH3CHClCHClCH2CH3
76. (CH3)2CHCH2CH2OH
77.
78.
or
Page 19