Ionic bonding results from the transfer of electrons from one atom to
another.
B.
Dipole moments result from the unequal distribution of electrons in a
molecule.
C.
The electrons in a polar bond are found nearer to the more electronegative
element.
D.
A molecule with very polar bonds can be nonpolar.
E.
Linear molecules cannot have a net dipole moment.
2.
Choose the compound with the most ionic bond.
A.
LiCl
B.
KF
C.
NaCl
D.
LiF
E.
KCl
3.
Which of the following bonds is least polar?
A.
C–O
B.
H–C
C.
S–Cl
D.
Br–Br
E.
They are all nonpolar.
4.
For the elements Cs, F, and Cl, the order of increasing electronegativity is:
A.
F < Cl < Cs
B.
Cs < Cl < F
C.
Cl < Cs < F
D.
F < Cs < Cl
E.
None of these
5.
What is the correct order of the following bonds in terms of decreasing polarity?
A.
N-Cl, P-Cl, As-Cl
B.
P-Cl, N-Cl, As-Cl
C.
As-Cl, N-Cl, P-Cl
D.
P-Cl, As-Cl, N-Cl
E.
As-Cl, P-Cl, N-Cl
6.
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
7.
Choose the molecule with the strongest bond.
A.
F2
B.
Cl2
C.
Br2
D.
I2
8.
Using the following bond energies
Bond
Bond Energy (kJ/mol)
CºC
839
C–H
413
O=O
495
C=O
799
O–H
467
estimate the heat of combustion for one mole of acetylene: C2H2(g) + (5/2)O2(g) ® 2CO2(g) + H2O(g)
A.
1228 kJ
B.
–1228 kJ
C.
–447 kJ
D.
+447 kJ
E.
+365 kJ
9.
Which of the following species is best described by drawing resonance structures?
A.
PH3
B.
NH4+
C.
O3
D.
SO3–
E.
HCN
10.
Using the following electronegativity values
C
2.5
Cl
3.2
H
2.2
N
3.0
O
3.4
select from the following group the molecule that fits the given statement:
a) CH3CHO
b) CO2
c) CH3Cl
d) C2H6
e) none
This molecule is the most polar.
Answer:
11.
Which of the following molecules is non-polar overall?
A.
SF4
B.
SF2
C.
CCl4
D.
H2S
E.
OCl2
12.
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.
13.
Write the resonance structures and predict the better (best) representation of the electrons due to formal charge:
CNO–
Answer:
14.
Find the best overall Lewis structure for POCl3 in which the P is surrounded by O and Cl.
Answer:
15.
Complete the Lewis structure for the molecule: This molecule has __________ single bonds and __________ multiple bonds.
A.
4, 2
B.
6, 3
C.
11, 5
D.
11, 2
E.
13, 0
16.
Which of the following is a valid Lewis structure for I3–?
A.
B.
C.
D.
E.
none of these
17.
Select the correct molecular structure for the given species from the choices below:
a) pyramidal
b) none of these
c) octahedral
d) trigonal planar
e) bent
NCl3
Answer:
18.
Select the correct molecular structure for the given species from the choices below:
a) pyramidal
b) none of these
c) octahedral
d) trigonal planar
e) bent
XeFe5+
Answer:
19.
Select the correct molecular structure for the given species from the choices below:
a) pyramidal
b) none of these
c) octahedral
d) trigonal planar
e) bent
BeF3–
Answer:
20.
What type of structure does the XeOF2 molecule have?
A.
pyramidal
B.
tetrahedral
C.
T-shaped
D.
trigonal planar
E.
octahedral
21.
Select the correct molecular structure for the given species from the choices below:
a) pyramidal
b) tetrahedral
c) square planar
d) octahedral
e) none of these
IF4–
Answer:
22.
The hybridization of the phosphorus atom in the cation PH2+ is:
A.
sp2
B.
sp3
C.
dsp
D.
sp
E.
none of these
23.
In the molecule C2H4 the valence orbitals of the carbon atoms are assumed to be
A.
not hybridized.
B.
sp hybridized.
C.
sp2 hybridized.
D.
sp3 hybridized.
E.
dsp hybridized.
24.
Which of the following statements is (are) incorrect? I. The hybridization of boron in BF3 is sp2. II. The molecule XeF4 is nonpolar. III. The bond order of N2 is three. IV. The molecule HCN has two pi bonds and two sigma bonds.
A.
All four statements are correct.
B.
II is incorrect.
C.
I and IV are incorrect.
D.
II and III are incorrect.
E.
II, III, and IV are incorrect.
25.
The hybridization of the central atom in SF3+ is:
A.
sp
B.
sp2
C.
sp3
D.
dsp3
E.
d2sp3
26.
The hybridization of the central atom in KrF4O is:
A.
sp
B.
sp2
C.
sp3
D.
dsp3
E.
d2sp3
27.
Which of the following contains a pi bond?
A.
H2CO
B.
PF2
C.
C2H6
D.
HClO
E.
CCl4
28.
Consider the following Lewis structure Which statement about the molecule is false?
A.
There are 10 sigma and 2 pi bonds.
B.
C–2 is sp2 hybridized with bond angles of 120°.
C.
Oxygen is sp3 hybridized.
D.
This molecule contains 28 valence electrons.
E.
There are some H–C–H bond angles of about 109° in the molecule.
29.
What is the bond order of C2+?
A.
0
B.
1/2
C.
1
D.
1 1/2
E.
2
30.
Which of the following has the greatest bond strength?
A.
B2
B.
O2–
C.
CN–
D.
O2+
E.
NO–
31.
Which of the following statements is false?
A.
C2 is paramagnetic.
B.
C2 is diamagnetic.
C.
The carbon-carbon bond in C22– is stronger than the one in CH3CH3.
D.
The carbon-carbon bond in C22– is shorter than the one in CH3CH3.
E.
Two of the above.
32.
Which one of the following decreases as the strength of the attractive intermolecular forces increases?
A.
The heat of vaporization.
B.
The normal boiling temperature.
C.
The extent of deviations from the ideal gas law.
D.
The sublimation temperature of a solid.
E.
The vapor pressure of a liquid.
33.
Hydrogen bonds account for which of the following observation?
A.
Hydrogen naturally exists as a diatomic molecule.
B.
Hydrogen is easily combustible with oxygen.
C.
Water molecules are bent or "V-shaped".
D.
Air is more dense than hydrogen gas.
E.
For its molar mass, water has a high boiling point.
34.
Which of the following would you expect to have the highest boiling point?
A.
F2
B.
Cl2
C.
Br2
D.
I2
E.
All of these have the same boiling point.
35.
Which of the following is most likely to be a solid at room temperature?
A.
Na2S
B.
HF
C.
NH3
D.
N2
E.
H2O
36.
Which of the following should have the lowest boiling point?
A.
Na2S
B.
HF
C.
NH3
D.
N2
E.
H2O
37.
The molecules in a sample of solid SO2 are attracted to each other by a combination of
A.
London forces and H-bonding.
B.
H-bonding and ionic bonding.
C.
covalent bonding and dipole-dipole interactions.
D.
London forces and dipole-dipole interactions.
E.
none of these
38.
Which of the following statements about liquids is true?
A.
Droplet formation occurs because of the higher stability associated with increased surface area.
B.
Substances that can form hydrogen bonds will display lower melting points than predicted from periodic trends.
C.
London dispersion forces arise from a distortion of the electron clouds within a molecule or atom.
D.
Liquid rise within a capillary tube because of the small size lowers the effective atmospheric pressure over the surface of the liquid.
E.
The boiling point of a solution is dependent solely on the atmospheric pressure over the solution.
39.
In which of the following groups of substances would dispersion forces be the only significant factors in determining boiling points?
I.
Cl2
II.
HF
III.
Ne
IV.
KNO2
V.
CCl4
A.
I, III, V
B.
I, II, III
C.
II, IV
D.
II, V
E.
III, IV, V
40.
The elements of group 5A, the nitrogen family, form compounds with hydrogen having the boiling points listed below:
SbH3 –17°C, AsH3 –55°C, PH3 –87°C, NH3 –33°C
The first three elements illustrate a trend where the boiling point decreases as the mass decreases; however, ammonia (HH3) does not follow the trend because of
A.
dipole-dipole attraction.
B.
metallic bonding.
C.
hydrogen bonding.
D.
London dispersion forces.
E.
ionic bonding.
41.
On the basis of your knowledge of bonding in liquids and solids, arrange the following substances in order of highest to lowest melting temperature:
NaCl, Na, Cl2, SiO2
A.
Cl2, Na, NaCl, SiO2
B.
Na, NaCl, Cl2, SiO2
C.
SiO2, NaCl, Na, Cl2
D.
NaCl, SiO2, Na, Cl2
E.
SiO2, Na, NaCl, Cl2
42.
Which of the following processes must exist in equilibrium with the evaporation process when a measurement of vapor pressure is made?
A.
fusion
B.
vaporization
C.
sublimation
D.
boiling
E.
condensation
43.
Which of the compounds below is an example of a network solid?
A.
S8(s)
B.
SiO2(s)
C.
MgO(s)
D.
NaCl(s)
E.
C25H52(s)
44.
Which of the following statements is incorrect?
A.
Molecular solids have high melting points.
B.
The binding forces in a molecular solid include London dispersion forces.
C.
Ionic solids have high melting points.
D.
Ionic solids are insulators.
E.
All of these statements are correct.
45.
What is responsible for capillary action, a property of liquids?
A.
surface tension
B.
cohesive forces
C.
adhesive forces
D.
viscosity
E.
two of these
46.
You are given the following boiling point data:
a) water, H2O
100°C
b) methanol, CH3OH
64.96°C
c) ethanol, CH3CH2OH
78.5°C
d) diethyl ether, CH3OH2–O–CH2CH3
34.5°C
e) ethylene glycol, HO–CH2–CH2–OH
198°C
Which one of the above liquids would you expect to have the highest vapor pressure at room temperature?
Answer:
47.
Which best explains the following trend?
Element
b.p. (K)
He
4
Ne
25
Ar
95
Kr
125
Xe
170
A.
London dispersion forces
B.
dipole-dipole interaction
C.
hydrogen bonding
D.
Le Châtelier's principle
E.
none of these
48.
When one mole of benzene is vaporized at a constant pressure of 1.00 atm and at its boiling point of 353.0 K, 30.79 kJ of energy (heat) is absorbed and the volume change is +28.90 L. What is DH for this process? (1 L-atm = 101.3 J)
A.
24.95 kJ
B.
36.63 kJ
C.
28.72 kJ
D.
30.79 kJ
E.
27.87 kJ
49.
How much energy is needed to convert 64.0 grams of ice at 0.00°C to water at 75.0°C?
specific heat (ice) = 2.10 J/(g°C)
specific heat (water) = 4.18 J/g(g°C)
heat of fusion = 333 J/g
heat of vaporization = 2258 J/g
A.
10.1 kJ
B.
20.7 kJ
C.
31.4 kJ
D.
41.4 kJ
E.
65.8 kJ
50.
The triple point of CO2 is at 5.2 atm and –57°C. Under atmospheric conditions present in a typical Boulder, Colorado, laboratory (P = 630 torr, T = 23°C), solid CO2 will:
A.
remain solid.
B.
boil.
C.
melt.
D.
sublime.
E.
none of these
51.
Choose the correct statement about the diagram below.
A.
The diagram is qualitatively correct for water.
B.
The diagram shows that the melting point of the solid increases with increasing pressure.
C.
The diagram shows the triple point above 1 atm pressure.
D.
The diagram could represent the phase diagram of CO2.
E.
None of these statements is correct.
52.
Shown below is a phase diagram for compound X. At 25°C and 1 atm X will exist as a:
A.
solid.
B.
liquid.
C.
gas.
D.
gas/liquid at equilibrium.
E.
gas/solid at equilibrium.
53.
Based on the phase diagram shown below, which of the following statements are correct?
I.
Sublimation occurs at a point in the transformation that occurs along a straight line
from point A to point F.
II.
C and E represent points where the gas and liquid phases are in equilibrium.
III.
DHvap can be measured at point B.
IV.
Molecules at point D have a greater average kinetic energy than those at point F.
V.
The temperature at point E is called the critical temperature of the compound.
A.
II, V
B.
I, III, IV
C.
I, II, III
D.
II, IV, V
E.
I, II, IV
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