B)
I, III, IV, VI
C)
III, V, VI
D)
I, IV, VI
E)
I, II, IV, VI
79. These molecules have a zero net dipole moment.
A)
III, V
B)
I, III, IV
C)
III, IV, V
D)
I, III, IV, VI
E)
none of them
80. These molecules have a trigonal bipyramidal electron pair arrangement.
A)
II, IV, VI
B)
I, IV
C)
IV, VI
D)
VI only
E)
none of them
81. Select the best Lewis structure for acetone, CH3COCH3.
A)
B)
C)
D)
E)
82. Which of the following exhibits resonance?
A)
NH3
B)
PCl5
C)
H2O
D)
O3
E)
At least two of the molecules (A-D) exhibit resonance.
83. Which of the following species is best described by drawing resonance structures?
A)
PH3
B)
NH4+
C)
O3
D)
SO3
E)
HCN
84. In the cyanide ion (CN–), the nitrogen has a formal charge of
A)
-2
B)
-1
C)
0
D)
2
E)
More information is needed.
85. Which has the greater N–O bond length, NO2– or NO3–?
A)
NO2–
B)
NO3–
C)
The bond lengths are the same.
D)
More information is needed.
E)
None of these (A-D).
86. How many resonance structures can be drawn for the molecule O3?
A)
1
B)
2
C)
3
D)
4
E)
5
87. Choose the electron dot formula that most accurately describes the bonding in CS2. (Hint:
Consider formal charges.)
A)
B)
C)
D)
E)
88. Which of the following has a Lewis structure most like that of CO32–?
A)
CO2
B)
SO32–
C)
NO3–
D)
O3
E)
NO2
89. Which of the following is not a valid resonance structure for N3–?
A)
B)
C)
D)
E)
all are correct
90. How many of the following molecules possess dipole moments?
BH3, CH4, PCl5, H2O, HF, H2
A)
1
B)
2
C)
3
D)
4
E)
5
91. Which of the following molecules has a dipole moment?
A)
CH4
B)
CCl4
C)
CO2
D)
SO2
E)
none of these
92. Select the molecule from the following that has a dipole moment.
A)
CO2
B)
SeO3
C)
XeF4
D)
SF4
E)
BeCl2
93. Which of the following molecules (or ions) has a dipole moment?
A)
CO2
B)
CO32–
C)
NH4+
D)
PF3
E)
two of them
94. Which of the following molecules has a dipole moment?
A)
BH3
B)
SiF4
C)
PF3
D)
O2
E)
none of these
95. Choose the statement that best describes the PbCl4 molecule in the gas phase.
A)
The bond angles are all about 109°.
B)
The molecule is polar.
C)
The molecule has a dipole moment.
D)
The bonds are nonpolar.
E)
More than one of the above.
96. Which of the following has a zero dipole moment?
A)
NH3
B)
NO2
C)
PF5
D)
SO2
E)
HCN
97. Which of the following types of molecules always has a dipole moment?
A)
Linear molecules with two identical bonds.
B)
Tetrahedral molecules (four identical bonds equally spaced).
C)
Trigonal pyramid molecules (three identical bonds).
D)
Trigonal planar molecules (three identical bonds equally spaced).
E)
None has a dipole moment.
98. Consider the following drawings:
Which of the following statements are true?
I.
The electrons in each molecule tend to orient themselves around the most
electronegative element.
II.
Each molecular drawing follows the localized electron model.
III.
Both HF and CO2 are linear molecules and therefore polar.
IV.
The bond angles of NH3 are slightly less than 109.5° because the lone pair
compresses the angles between the bonding pairs.
A)
I, III, IV
B)
I, II, IV
C)
I, II, III
D)
II, IV
E)
All of the above statements are correct.
99. If a compound has a number of individual dipoles, then:
I.
It is polar overall.
II.
There is an electronegativity difference between the bonded atoms.
III.
it is ionic.
IV.
It doesn’t have resonance.
A)
II only
B)
II, IV
C)
I, II, IV
D)
I, III
E)
All of the above statements are correct.
100. Of the following, which molecule has the largest bond angle?
A)
O3
B)
OF2
C)
HCN
D)
H2O
E)
More than one of the above have equally large bond angles.
101. According to the VSEPR model, the arrangement of electron pairs around NH3 and CH4 is
A)
different, because in each case there are a different number of atoms around the
central atom
B)
different, because in each case there are a different number of electron pairs around
the central atom
C)
the same, because both nitrogen and carbon are both in the second period
D)
the same, because in each case there are the same number of electron pairs around
the central atom
E)
different or the same, depending on the conditions leading to maximum repulsion
102. The Cl–Kr–Cl bond angle in KrCl4 is closest to
A)
90°
B)
109°
C)
120°
D)
150°
E)
360°
103. How many of the following molecules—SF2, SF4, SF6, SiO2—are polar?
A)
0
B)
1
C)
2
D)
3
E)
4
104. Which of the following molecules is non-polar overall?
A)
SF4
B)
SF2
C)
CCl4
D)
H2S
E)
OCl2
105. Which of the following is the correct order for molecules from most to least polar?
A)
CH4 > CF2Cl2 > CF2H2 > CCl4 > CCl2H2
B)
CH4 > CF2H2 > CF2Cl2 > CCl4 > CCl2H2
C)
CF2Cl2 > CF2H2 > CCl2H2 > CH4 = CCl4
D)
CF2H2 > CCl2H2 > CF2Cl2 > CH4 = CCl4
E)
CF2Cl2 > CF2H2 > CCl4 > CCl2H2 > CH4
106. Which of the following molecules has a nonlinear structure?
A)
XeF2
B)
BeCl2
C)
O3
D)
CO2
E)
N2O (central atom is N)
107. Which of the following molecules are nonlinear?
NO2–, C2H2, N3–, HCN, CO2, H2O2
A)
C2H2, HCN
B)
CO2, N3–
C)
NO2–, H2O2
D)
N3–, NO2–
E)
all are linear
108. How many of the following molecules or ions are linear?
NH3
OF2
HCN
CO2
NO2
A)
0
B)
1
C)
2
D)
3
E)
4
109. The molecular structure of SOCl2 is
A)
pyramidal
B)
none of these
C)
octahedral
D)
trigonal planar
E)
bent
110. The molecular structure of OF2 is
A)
pyramidal
B)
none of these
C)
octahedral
D)
trigonal planar
E)
bent
111. The molecular structure of NCl3 is
A)
pyramidal
B)
none of these
C)
octahedral
D)
trigonal planar
E)
bent
112. The molecular structure of BeF3– is
A)
pyramidal
B)
none of these
C)
octahedral
D)
trigonal planar
E)
bent
113. The molecular structure of BrF6+ is
A)
pyramidal
B)
none of these
C)
octahedral
D)
trigonal planar
E)
bent
114. The molecular structure of AsCl5 is
A)
trigonal bipyramidal
B)
square pyramidal
C)
distorted tetrahedral
D)
octahedral
E)
none of these
115. The molecular structure of XeF5+ is
A)
trigonal bipyramidal
B)
square pyramidal
C)
distorted tetrahedral
D)
octahedral
E)
none of these
116. What type of structure does the XeOF2 molecule have?
A)
pyramidal
B)
tetrahedral
C)
T-shaped
D)
trigonal planar
E)
octahedral
117. The bond angles about the carbon atom in the formaldehyde molecule, H2C=O, are about:
A)
120°
B)
60°
C)
109°
D)
180°
E)
90°
118. Which of the following species has a trigonal bipyramid structure?
A)
NH3
B)
IF5
C)
I3–
D)
PCl5
E)
none of these
119. The bond angle in H2Se is about:
A)
120°
B)
60°
C)
180°
D)
109°
E)
90°
120. Which ion is planar?
A)
NH4+
B)
CO32–
C)
SO32–
D)
ClO3–
E)
all are planar
Select the correct molecular structure for the given species from the choices below:
121. PF6–
A)
pyramidal
B)
tetrahedral
C)
square planar
D)
octahedral
E)
none of these
122. PCl4+
A)
pyramidal
B)
tetrahedral
C)
square planar
D)
octahedral
E)
none of these
123. XeF6
A)
pyramidal
B)
tetrahedral
C)
square planar
D)
octahedral
E)
none of these
124. NI3
A)
pyramidal
B)
tetrahedral
C)
square planar
D)
octahedral
E)
none of these
125. SiH4
A)
pyramidal
B)
tetrahedral
C)
square planar
D)
octahedral
E)
none of these
126. ClO2
A)
pyramidal
B)
tetrahedral
C)
square planar
D)
octahedral
E)
none of these
127. IF4–
A)
pyramidal
B)
tetrahedral
C)
square planar
D)
octahedral
E)
none of these
128. SO32–
A)
pyramidal
B)
tetrahedral
C)
square planar
D)
octahedral
E)
none of these
Select the correct molecular structure for the given species from the choices below:
129. H2O
A)
linear
B)
trigonal planar
C)
tetrahedral
D)
bent
E)
none of these
130. CO2
A)
linear
B)
trigonal planar
C)
tetrahedral
D)
bent
E)
none of these
131. BeCl2
A)
linear
B)
trigonal planar
C)
tetrahedral
D)
bent
E)
none of these
132. SF4
A)
linear
B)
trigonal planar
C)
tetrahedral
D)
bent
E)
none of these
133. NO3–
A)
linear
B)
trigonal planar
C)
tetrahedral
D)
bent
E)
none of these
134. I3–
A)
linear
B)
trigonal planar
C)
tetrahedral
D)
bent
E)
none of these
135. PF5
A)
linear
B)
trigonal planar
C)
tetrahedral
D)
bent
E)
none of these
136. ClF2+
A)
linear
B)
trigonal planar
C)
tetrahedral
D)
bent
E)
none of these
137. In the molecule XeF2, how many pairs of electrons surround Xe and what is the molecular
geometry?
A)
4, bent
B)
4, pyramidal
C)
5, linear
D)
5, bent
E)
6, linear
138. According to VSEPR theory, which of the following species has a square planar molecular
structure?
A)
TeBr4
B)
BrF3
C)
IF5
D)
XeF4
E)
SCl2
139. How many of the following molecules have all of their atoms in the same plane?
H2C=CH2
OF2
H2CO
NH3
CO2
BeCl2
A)
3
B)
4
C)
5
D)
6
E)
7
140. The shape of an ammonia molecule is tetrahedral.
141. The shape of a carbon dioxide molecule is linear.
142. When nonmetals chemically combine, they tend to form what type of bond?
143. The ability of an atom in a molecule to attract shared electrons to itself is called
__________.
144. A molecule that has a center of positive charge and a center of negative charge is said to be
__________.
145. Match the ions below with the pictures that represent their relative sizes. Justify your
answers.
Ions:
Se2– K+ Ga3+ Br– Ca2+
146. The __________ is the change in energy that takes place when separated gaseous ions are
packed together to form an ionic solid.
147. Stable molecules usually contain atoms that have filled __________ orbitals.
148. The __________ of a molecule shows how the valence electrons are arranged among the
atoms in the molecule.
149. When several nonequivalent Lewis structures can be drawn for a molecule, __________ is
used to determine the most appropriate structure(s).
150. In spite of larger electronegativity differences between bonded atoms, BeCl2 has no dipole
while SCl2 does. Explain fully.
151. AlF3
152. NH3
153. ICl4–
154. CBrI3