79. NiCl42– (tetrahedral)
A)
0
B)
1
C)
2
D)
4
E)
5
80. CoF63– (weak field)
A)
0
B)
1
C)
2
D)
4
E)
5
81. Co(en)33+ (strong field)
A)
0
B)
1
C)
2
D)
4
E)
5
82. Mn(H2O)43+ (tetrahedral)
A)
0
B)
1
C)
2
D)
4
E)
5
83. 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–
.
A)
0
B)
1
C)
2
D)
3
E)
4
84. According to crystal field theory, how many unpaired electrons are present in the complex
ion [Fe(H2O)6]2+? The water molecules are weak field ligands.
A)
1
B)
2
C)
3
D)
4
E)
5
85. How many unpaired electrons are present in the tetrahedral complex [CoCl4]–?
A)
1
B)
2
C)
3
D)
4
E)
5
86. Which has the greatest number of unpaired electrons?
A)
The square planar complex Ni(CN)42–.
B)
The tetrahedral complex FeCl4–.
C)
Neither of the above have any unpaired electrons.
D)
Both (A and B) have the same number (non-zero) of unpaired electrons.
E)
More information is needed.
87. A d6 ion (Fe2+) is complexed with six strong-field ligands (for example, SCN–). What is the
number of unpaired electrons in this complex?
A)
0
B)
1
C)
2
D)
3
E)
4
88. How many unpaired electrons are there in Ir(Br)64–? (Br– is a weak-field ligand.)
A)
4
B)
3
C)
2
D)
1
E)
0
89. The complex ion NiCl42– is tetrahedral. The number of unpaired electrons in the complex is:
A)
0
B)
1
C)
2
D)
3
E)
4
90. How many unpaired electrons are there in the tetrahedral complex ion [FeCl4]–?
A)
1
B)
2
C)
3
D)
4
E)
5
91. A metal ion in a high-spin octahedral complex has two more unpaired electrons than the
same ion does in a low-spin octahedral complex. The metal ion could be:
A)
V2+
B)
Cu2+
C)
Mn2+
D)
Cr3+
E)
Co2+
92. For which of the following metal ions would there be no low-spin versus high-spin
distinction in octahedral complexes?
A)
Cr2+
B)
V2+
C)
Fe3+
D)
Mn2+
E)
Co3+
93. How many unpaired electrons are there in a complex ion having a d5 electron configuration
and an octahedral geometry in the weak field case?
A)
1
B)
2
C)
3
D)
4
E)
5
94. The spectrochemical series is I– < Br– < Cl– < F– < OH– < H2O < NH3 < en < NO2– < CN–
Which of the following complexes will absorb visible radiation of the highest energy
(shortest wavelength)?
A)
[Co(H2O)6]3+
B)
[Co(I)6]3–
C)
[Co(OH)6]3–
D)
[Co(en)3]3+
E)
[Co(NH3)6]3+
Here are some crystal field representations of d electrons in an octahedral complex:
I)
II)
III)
IV)
V)
Choose the representation that fits the transition metal atom in the following species:
95. Fe(OH2)63+ (assume weak field)
A)
representation I
B)
representation II
C)
representation III
D)
representation IV
E)
representation V
96. [Co(NH3)4Br2]+
A)
representation I
B)
representation II
C)
representation III
D)
representation IV
E)
representation V
ANS: B PTS: 1 DIF: Moderate REF: 21.6
KEY: Chemistry | general chemistry | transition elements | complex ions and coordination
compounds | crystal field theory | octahedral complex MSC: Conceptual
97. K4Mn(CN)6 (assume strong field)
A)
representation I
B)
representation II
C)
representation III
D)
representation IV
E)
representation V
98. K4Fe(CN)6
A)
representation I
B)
representation II
C)
representation III
D)
representation IV
E)
representation V
99. [Cr(NH3)5Cl]SO4
A)
representation I
B)
representation II
C)
representation III
D)
representation IV
E)
representation V
100. A complex ion is a square planar complex. It has a d8 electron configuration. What is the
most reasonable d orbital scheme for this complex?
A)
B)
C)
D)
E)
101. 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
102. Which of the following crystal field diagrams is correct for Mn(CN)63– (CN– is a strong field
ligand)?
A)
B)
C)
D)
E)
none of these
103. Choose the most likely pattern for the crystal field diagram for the complex trans–
[Ni(NH3)2(CN)4]2– where CN– produces a much stronger crystal field than does NH3.
A)
B)
C)
D)
E)
104. Which of the following is true in describing the crystal field model?
A)
The metal ion and ligand interaction is treated as a Lewis acid–base interaction.
B)
The ligands are treated as negative point charges.
C)
The metal ion–ligand bonds are considered to be completely ionic.
D)
The electrons are assumed to be localized.
E)
None of the above is true.
105. Which model(s) accounts for the magnetism and color of coordination compounds?
I.
Lewis model
II.
localized electron model
III.
crystal field model
A)
I
B)
II
C)
III
D)
I, II
E)
none accounts for both phenomena
106. Which of the following complexes would be diamagnetic (all electrons paired)? Assume the
strong-field case for all complexes.
A)
[Ni(CN)6]4–
B)
[Ti(CN)6]3–
C)
[Co(CN)6]3–
D)
[Cr(CN)6]3–
E)
none of these
107. How many unpaired electrons are there in the complex ion [Co(NO3)6]4–? For this ion the
nitrate ligands produce a very strong crystal field.
A)
1
B)
2
C)
3
D)
4
E)
5
108. A certain complex ion has a distorted octahedral structure in which the ligands along the
plus and minus z axes are compressed (pushed in closer to the central metal ion). The d
orbital splitting diagram for this complex ion would be:
A)
________
________
________ ________
________
B)
________ ________
________ ________ ________
C)
________
________
________
________ ________
D)
________ ________ ________
________ ________
E)
________ ________
________
________
________
109. The color of a transition metal complex results from:
A)
bending vibrations
B)
stretching vibrations
C)
transition of an electron between d orbitals
D)
transition of an electron between an s and a p orbital
E)
nuclear magnetic resonance
110. The complex ion Fe(CN)64– (no unpaired electrons) is classified as:
A)
weak field
B)
strong field
C)
no way to tell
111. The complex ion Co(NH3)62+ (three unpaired electrons) is classified as:
A)
weak field
B)
strong field
C)
no way to tell
112. The complex ion Ni(NH3)62+ (two unpaired electrons) is classified as:
A)
weak field
B)
strong field
C)
no way to tell
113. All tetrahedral complex ions are high spin.
114. The complex ions containing Zn2+ are intensely colored.
115. The complexes of Zn2+ are all diamagnetic.
116. In the crystal field model, ligands are treated as negative point charges.
117. Cytochromes consist of two main parts:
A)
myoglobin and heme
B)
heme and porphyrin
C)
heme and a protein
D)
myoglobin and porphyrin
E)
an iron ion and porphyrin
118. Hemoglobin is a complex of
A)
Co3+
B)
Mg2+
C)
Fe2+
D)
Sc3+
E)
none of these
119. The iron in hemoglobin is ______ when carrying oxygen to cells, and _______ after
releasing the oxygen.
A)
diamagnetic Fe2+, paramagnetic Fe3+
B)
diamagnetic Fe2+, paramagnetic Fe2+
C)
paramagnetic Fe2+, diamagnetic Fe3+
D)
paramagnetic Fe3+, diamagnetic Fe3+
E)
none of these
120. Oxygen is stored in mammalian tissue in which type of molecule?
A)
hemoglobin
B)
myoglobin
C)
chlorophyll
D)
cytochrome
E)
prophyrin
121. The transition metal __________ assists insulin in the control of blood sugar and may also
be involved in the control of cholesterol.
A)
scandium
B)
titanium
C)
iron
D)
nickel
E)
chromium
122. The transition metal __________ is present in vitamin B12.
A)
nickel
B)
titanium
C)
cobalt
D)
zinc
E)
chromium
123. This molecule is toxic because it has about 200 times the affinity for the Fe2+ in hemoglobin
as oxygen does, causing asphyxiation if enough of it is present in the air.
A)
CN–
B)
CO
C)
CO2
D)
NH3
E)
CH4
124. Carboxyhemoglobin is formed when __________ prevents the normal uptake of oxygen in
the blood.
A)
CN–
B)
CO
C)
CO2
D)
NH3
E)
CH4
125. When the body adapts to high altitudes, it makes more __________ to adapt to lower
oxygen concentrations in the blood.
A)
myoglobin
B)
iron
C)
protein
D)
hemoglobin
E)
fatty tissue
126. Which of the following materials is added to the blast furnace to produce slag?
A)
sulfur
B)
carbon
C)
silicon
D)
limestone
E)
none of these
127. Name the careful heat treatment of metals that provides the proper combination of strength
without too much brittleness.
A)
tempering
B)
core hardening
C)
fire polishing
D)
blast furnace
E)
direct reduction
128. Which of the following is not a typical step in metallurgy?
A)
reduction
B)
refining
C)
alloying
D)
roasting
E)
transmutation
129. Pig iron usually contains about 5%:
A)
aluminum
B)
oxygen
C)
sodium
D)
sulfur
E)
carbon
130. The strength of steel is due to the effect of what substance with the iron?
A)
copper
B)
carbon monoxide
C)
sulfur
D)
carbon
E)
zinc
131. Which of the following ligands are capable of linkage isomerism?
N–
NO2–
NH3
NH2CH2CH2NH2
OCN–
Cl–
H2O
SCN–
132. Define stereoisomerism.
133. Define optical isomerism.
134. Consider the pseudo-octahedral complex of Cr3+ shown below, where A and B represent
Lewis bases and where A produces a stronger crystal field than B. Draw an appropriate
crystal field diagram for this complex (include the electrons).
135. The 3d electrons in Co(NH3)63+ are all paired but Fe(H2O)63+ has unpaired electrons (is
paramagnetic). Explain.
How many unpaired electrons are found in each of the following complex ions?
136. CoBr4– (tetrahedral)
137. Fe(CN)64–
138. [Zn(CN)6]4–
139. NiCl42–
140. FeCl42–
141. [Ni(CN)6]4–
142. [Cr(CN)4]2–
