AP CHEM – Chemical Bonding and Molecular Shape
Kaplan: Chemical Bonding and Molecular Shape
1. Which does not make a good electron donor in the formation of a
coordinate covalent bond?
a. Clb. H2O
c. PF3
d. CH4
e. NH3
2. In the molecule shown, in which bond is the electron density shifted
furthest away from the carbon atom? (EN values: C=2.5, H=2.1, Cl=3.0,
Br=2.8, O=3.5)
a.
b.
c.
d.
e.
The C-H bond only
The C-O bond only
The C-Cl bond only
The C-Br bond only
The C-Cl and the C-Br bond
3. The formate ion, HCO2-, has two equivalent bonds from the carbon atom
to each oxygen atom. Each bond is intermediate in length between a
single bond and a double bond. Resonance theory is used to describe
bonding in this ion. Which is an acceptable resonance structure for this
ion?
I.
III.
II.
IV.
1
a.
b.
c.
d.
e.
II only
I and III only
II and IV only
I, II, and III only
I, II, III and IV
4. Which statement is true of a chemical species that donates electrons to a
coordinate covalent bond?
a. It is a metal ion.
b. It is a noble gas atom.
c. It violates the octet rule.
d. It has only nonpolar bonds.
e. It has a lone pair of valence electrons.
5. Which of these atoms doesn’t always obey the octet rule?
H
a.
b.
c.
d.
e.
Cl
O
H only
Cl only
O only
Both H and Cl
Both H and O
6. What are the formal charges respectively of N, C, and O in this resonance
form of the cyanate ion (NCO-)?
a.
b.
c.
d.
e.
0, 0, 0
0, 0, -1
-1, 0, 0
-1, +1, -1
-2, 0, +1
2
7. The molecule thionyl bromide, SOBr2, has three skeleton structures. Using
the formal charges and electronegativity, which is the most preferred?
(EN values Br=2.8, O=3.5, S=2.5)
I.
a.
b.
c.
d.
e.
II.
III.
I
II
III
I and II are equally preferred over III
II and III are equally preferred over I
8. The structures of three nitrogen-containing compounds are shown. Match the
name of the compound to the correct C to N bond length.
Compounds:
H3C-NH2 (methylamine)
H3CC=N (acetonitrile)
CH3CH2CH=NCH2CH3 (N-ethylpropanalimine)
85 pm
a.
b.
c.
116 pm
Bond Lengths
124 pm
147 pm
200 pm
116 pm
H3C-NH2
124 pm
CH3CH2CH=NCH2CH3
147 pm
H3CC N
116 pm
H3CC N
124 pm
CH3CH2CH=NCH2CH3
147 pm
H3C-NH2
85 pm
H3C-NH2
124 pm
CH3CH2CH=NCH2CH3
200 pm
H3CC N
3
9. How much energy is needed to completely dissociate one mole of H3C-CN
(acetonitrile) into its atoms?
C N
891
a.
b.
c.
d.
e.
Bond Energies in kJ
C-C
N-H
347
391
C-H
413
1,891 kJ
2,130 kJ
1,651 kJ
2,201 kJ
2,477 kJ
10. Which molecule has a Lewis structure that is an expanded octet?
a. IF5
b. BF4c. SO32d. BrF2+
e. Cl2SO
11. Combining one s and two p orbitals creates:
a. one sp2 hybrid orbital
b. one sp hybrid orbital
c. two sp3 hybrid orbitals
d. three sp hybrid orbitals
e. three sp2 hybrid orbitals
12. What are the electron pair geometry and the molecular geometry of SF4?
a. trigonal bipyramidal: seesaw
b. trigonal bipyramidal: T-shaped
c. trigonal bipyramidal: trigonal bipyramidal
d. Octahedral: square planar
e. Octahedral: square pyramidal
4
13. Which of the statements about the IF5 molecule is (are) true?
I.
All its bond angles are identical.
II.
It has no net dipole moment
III.
It contains polar bonds
a. I only
b. II only
c. III only
d. I and II only
e. I and III only
14. The boron atom in boron tribromide has sp2 hybridization. What are the
angles between the bromine atoms in BBr3?
a. All angles are 90o
b. Two angles are 90o and the other is 120o
c. All angles are 120o
d. Two angles are 120o and the other is 180o
e. All angles are 180o
15. What is the hybridization of the central selenium atom of selenium
hexafluoride, SeF6?
a. sp5
b. s2p3d
c. spd2
d. sp3d
e. sp3d2
16. The diagram below shows the arrangement of electron groups in a
molecule with octahedral electron pair geometry and a square pyramidal
molecular geometry. Where will the next lone pair most likely be located
if one more external atom is absent?
a.
b.
c.
d.
e.
Position I only
Position II only
Position III only
Position I or Position II
Position I, Position II, or Position III
5
Kaplan Chemical Bonding and Molecular Shape Answers
1. D
5. D
9. E
2. B
6. C
10. A
3. B
7. B
11. E
4. E
8. B
12. A
13. E
14. C
15. E
16. A
Peterson’s Molecular Geometry
1. Types of hybridization exhibited by the C atoms in acetylene, C2H2,
include which of the following?
I. sp
II. sp2
III. sp3
a.
b.
c.
d.
e.
I only
III only
I and II only
II and III only
I, II, and III
2. Which of the following diatomic molecules has the largest bonddissociation energy?
a. Li2
b. Be2
c. B2
d. N2
e. O2
3. Which of the following diatomic molecules has the shortest bond
length?
a. Li2
b. Be2
c. B2
d. N2
e. O2
6
4. Which of the following diatomic elements contains only 1 sigma (σ) and 1
pi (π) bond?
a. Li2
b. Be2
c. B2
d. N2
e. O2
5. In a molecule in which the central atom exhibits sp3d hybrid orbitals, the
electron pair arrangements form the shape of
a. a tetrahedron.
b. A square-based pyramid.
c. A trigonal bipyramidal.
d. A square
e. An octahedron
6. Molecules that have planar configurations include which of the following?
I. BF3
II. XeF4
III. NH3
a.
b.
c.
d.
e.
I only
III only
I and II only
II and III only
I, II and III
7. The electron-dot structure (Lewis structure) for which of the following
molecules would have one unshared pairs of electrons on the central
atom?
a. H2O
b. NH3
c. CH4
d. C2H2
e. CO2
7
8. Which of the following molecules has a trigonal pyramidal shape?
a. PCl5
b. N2O
c. NH3
d. CCl4
e. H2O2
9. The AsF5 molecule has a trigonal bipyramidal structure. Therefore, the
hybridization of As orbitals should be
a. sp2
b. sp3
c. sp2d
d. sp3d
e. sp3d2
CCl4, BeF2, PCl3, SbCl5, XeF4
10. Which of the following does not describe any of the molecules above?
a. linear
b. octahedral
c. square planar
d. tetrahedral
e. trigonal pyramidal
11. The geometry of the H2S molecule is best described as
a. trigonal planar
b. trigonal pyramidal
c. square pyramidal
d. bent
e. tetrahedral
12. All of the molecules below display sp3d hybridization EXCEPT
a. NF3
b. PF5
c. SF4
d. BrF3
e. XeOF2
8
13. Pi bonding occurs in each of the following species EXCEPT
a. N2F2
b. C2H2
c. HCN
d. C6H6
e. CCl4
14. Antibonding orbitals are found
a. between the nuclei of atoms.
b. surrounding the nuclei of atoms.
c. nowhere; they only exist theoretically.
d. on the outsides of atoms (the sides opposite the overlapping
regions).
e. above the bonding orbitals.
15. Which of the following has a dipole moment of zero?
a. CCl4
b. HCN
c. NO2
d. NH3
e. H2O
Peterson’s Molecular Geometry Answers
1.a
5.c
2.d
6.c
3.d
7.b
4.e
8.c
9.d
10.b
11.d
12.a
13.e
14.d
15.a
Peterson’s Chemical Bonding
1. The energy required to remove an electron from a gaseous atom is known as
a. activation energy
b. free energy
c. ionization energy
d. kinetic energy
e. lattice energy
9
2. The energy required to separate an ionic solid into gaseous ions is known as
a. activation energy
b. free energy
c. ionization energy
d. kinetic energy
e. lattice energy
3. For which of the following molecules are resonance structures necessary to
describe the bonding satisfactorily?
a. H2O
b. SO2
c. C2H6
d. HCN
e. PF3
4. Which of the following has the most polar bond?
a. N2
b. F2
c. HF
d. HCl
e. PCl3
5. Which of the following would most likely have the highest boiling point?
a. NH3
b. CH4
c. PCl5
d. HF
e. LiCl
10
Use these answers for questions 6-8
a. hydrogen bonding
b. hybridization
c. ionic bonding
d. resonance
e. London dispersion forces
6. Is used to explain why bromine molecules are held together in the liquid state
at room temperature
7. Is used to explain why the boiling point of a n-propanol, C3H7OH, is greater
than the boiling point of propane, C3H8
8. Is used to explain the fact that the S-O bonds in SO3 are identical.
9. Which of the following elements, if placed as the central atom in a molecule,
is capable of having more than 8 valence electrons.
a. N
b. F
c. O
d. Te
e. H
10. Which molecule has a Lewis structure that does not obey the octet rule?
a. NO
b. CS2
c. PF3
d. HCN
e. CCl4
Peterson’s Chemical Bonding Answers
1. c
5.
2. e
6.
3. b
7.
4. c
8.
e
e
a
d
9. d
10. a
11
Barron’s: Covalent Compounds, Formulas, and Structure
1. In which of the following are the elements listed in order of increasing
electronegativity?
a. Ba, Zn, C, Cl
b. N, O, S, Cl
c. N, P, As, Sb
d. K, Ba, Si, Ga
e. Li, K, Na, Ca
2. Which of the following bonds is expected to be the most polar?
a. C-Si
b. C-N
c. O-C
d. S-C
e. H-C
3. For which of the following may we draw both polar and nonpolar structures?
a. CHCl3
b. NH3
c. BF3
d. SF2Cl4
e. PCl5
4. Which of the following has the fewest pi bonds and is nonpolar?
a. HCCH
b. CO2
c. CO3-2
d. N2
e. SO2
5. The SF5- ion has a square pyramid structure. The hybidization of the S
orbitals in sulfur is
a. dsp3
b. sp
c. d2sp3
d. sp3
e. sp2
12
6. Which of the following is NOT a linear structure?
a. I2
b. I3c. CO2
d. H2S
e. H-C C-H
7. The Lewis structure of the cyanide ion most closely resembles
a. N2
b. O2
c. CO2
d. NO
e. C2H2
8. In which of the following pairs are the two items NOT properly related?
a. sp3 and 109.5o
b. trigonal planar and 120o
c. octahedral and dsp3
d. sp and 180o
e. square planar and d2sp3
9. How many resonance structures are possible for the SO3 molecule?
a. none
b. 2
c. 3
d. 4
e. 4/3
10. Which of the following has a nonbonding pair of electrons on the central atom?
a. BCl3
b. NH3
c. CCl2Br2
d. PF5
e. SO4-2
13
11. Which of the following is true when the C = C and the C C bonds are
compared?
a. The triple bond is shorter than the double bond.
b. The double bond vibrates at a lower frequency than the triple bond.
c. The double bond energy is lower than the triple-bond energy.
d. Both are composed of sigma and pi bonds.
e. All of the above are true.
12. How many electrons are available to construct the Lewis structure of the
sulfite ion?
a. 24
d. 22
b. 18
e. 20
c. 26
13. The correct name for N2O3 is
a. dinitrogen tetroxide
b. dinitrogen trioxide
c. dinitrogen oxide
d. trinitrogen dioxide
e. nitric anhydride
14. Which angle is NOT expected in any simple molecule?
a. 60o
b. 90o
c. 109.5o
d. 120o
e. All of these are reasonable angles.
15. Sulfur forms the following compounds: SO2, SF6, SCl4, SCl2. Which form
of hybridization is NOT represented by these molecules?
a. sp
b. sp2
c. sp3
d. dsp3
e. d2sp3
14
Barron’s: Covalent Compounds, Formulas, and Structure Answers
1.a
5.c
9.c
13.b
2.c
6.d
10.b
14.a
3.d
7.a
11.e
15.a
4.c
8.c
12.c
Peterson’s States of Matter – Liquids and Solids
1. 1-propanol boils at 97 oC and ethyl methyl ether boils at 7 oC, although each
compound has an identical chemical composition. The difference that is
responsible for the higher boiling temperature is
a. molar mass
b. hydrogen bonding
c. density
d. specific heat
e. enthalpy
15
2. Which of the following is true at the triple point of a pure substance?
a. the temperature is equal to the normal melting point
b. all three states have identical densities
c. the solid-liquid equilibrium will always have a positive slope
moving upward from the triple point
d. the vapor pressure of the solid phase always equals the vapor
pressure of the liquid phase
e. the pressure is exactly one-half the critical pressure
For questions 3-5, use the key below. Select the description that best describes
the substance.
a.
b.
c.
d.
a network solid with covalent bonding
a molecular solid
an ionic solid
a metallic solid
3. Dry ice, solid carbon dioxide, CO2
4. Diamond, solid C
5. Brass, a mixture of copper and zinc
6. The critical temperature of a substance is the
a. temperature at which the vapor pressure of the liquid equals
normal atmospheric pressure
b. highest temperature at which a substance can exist in the liquid
state, regardless of pressure
c. temperature at which boiling occurs at 1.0 atm of pressure
d. temperature and pressure where solid, liquid, and vapor phases are
all in equilibrium
e. point at which pressure and temperature are less than 0
7. When the liquid metal mercury is placed in a small tube, the meniscus
actually curves upward, just the opposite of water. The reason for this is that
a. the cohesive force is greater than the adhesive force
b. the adhesive force is greater than the cohesive force
c. the density of mercury is much larger than water
d. the density of mercury is much greater where it is in contact with the glass
e. mercury is less volatile than water
16
Questions 8-11 refer to the phase diagram shown below:
a.
b.
c.
d.
e.
sublimation
condensation
solvation
fusion
freezing
8. If the temperature increases from 10 oC to 60 oC at a constant pressure of 0.5
atm, which process occurs?
9. If the temperature decreases from 100 oC to 60 oC at a constant pressure of 1.5
atm, which process occurs?
10. If the pressure increases from 0.5 atm to 1.5 atm at a constant temperature of
100 oC, which process occurs?
11. The normal boiling pont of the substance is approximately
a. 50 oC
b. 60 oC
c. 70 oC
d. 80 oC
e. 90 oC
17
12. Which of the following explains why, at room temperature, I2 is a solid, Br2 is
a liquid, and Cl2 is a gas?
a. hydrogen bonding
b. hybridization
c. ionic bonding
d. resonance
e. London dispersion forces
Peterson’s States of Matter-Liquids and Solids Answers
1. b
5. d
2. d
6. b
3. b
7. a
4. a
8. a
9. e
10. b
11. e
12. e
Cliff’s Covalent Bonding
1. What is the geometry of S2Cl2?
a. trigonal planar
b. tetrahedral
c. pyramidal
d. bent
e. linear
2. What is the geometry of OPN?
a. trigonal planar
b. tetrahedral
c. pyramidal
d. bent
e. linear
3. What is the geometry of SeO4-2?
a. trigonal planar
b. tetrahedral
c. pyramidal
d. bent
e. linear
18
4. What is the geometry of SiO3-2?
a. trigonal planar
b. tetrahedral
c. pyramidal
d. bent
e. linear
5. What is the geometry of the hydronium ion, H3O+?
a. trigonal planar
b. tetrahedral
c. pyramidal
d. bent
e. linear
6. Which one of the following is a nonpolar molecule with one or more polar
bonds?
a. H-Br
b. Cl-Be-Cl
c. H-H
d. H-O-H
e. K-Cl
7. How many total sigma bonds are in the benzene molecule, C6H6?
a. 6
b. 9
c. 12
d. 14
e. 18
8. Which one of the following does NOT exhibit resonance?
a. SO2
b. SO3
c. HI
d. CO3-2
e. NO3-
19
9. What type of hybridization would you expect to find in BCl3?
a. sp
b. sp2
c. sp3
d. sp3d2
e. no hybridization occurs in this molecule.
10. The electronegativity of carbon is 2.5, whereas that of oxygen is 3.5. What
type of bond would you expect to find in carbon monoxide?
a. nonpolar covalent
b. polar covalent
c. covalent network
d. ionic
e. delta
11. Which one of the following contains a coordinate covalent bond?
a. N2H5+
b. BaCl2
c. HCl
d. H2O
e. NaCl
12. What is the formal number of pairs of unshared valence electrons in the
NO2+ ion?
a. O
b. 2
c. 4
d. 8
e. 10
13. The bond energy of Br -Br is 192 kJ/mol, and that of Cl - Cl is 243 kJ/mol.
What is the energy of the Cl - Br bond?
a. 54.5 kJ/mol
b. 109 kJ/mol
c. 218 kJ/mol
d. 435 kJ/mol
e. 870 kJ/mol
20
Cliff’s Covalent Bonding Answers
1. d
5. c
2. e
6. b
3. b
7. c
4. a
8. c
9. b
10. b
11. a
12. c
13. c
Cliff’s Ionic Bonding
1. Which of the following is the electron configuration for Ni+2?
a. 1s22s22p63s23p64s23d6
b. 1s22s22p63s23p64s23d10
c. 1s22s22p63s23p63d8
d. 1s22s22p63s23p64s23d8
e. 1s22s22p63s23p64s23d4
2. As the atomic number of the elements increases down a column.
a. the atomic radius decreases
b. the atomic mass decreases
c. the elements become less metallic
d. ionization energy decreases
e. the number of electrons in the outermost energy level increases
3. What is the oxidation number of platinum in PtCl6-2?
a. -4
b. -2
c. -1
d. +4
e. +6
4. What type of bond would you expect in CsI?
a. Ionic
b. Covalent
c. Hydrogen
d. Metallic
e. Van der Waals
21
5. Arrange the following ions in order of increasing ionic radius: Mg+2, F-,
and O-2.
a. O-2, F-, Mg+2
b. Mg+2, O-2, Fc. Mg+2, F-, O-2
d. O-2, Mg+2, Fe. F-, O-2, Mg+2
6. Which of the following is the correct Lewis structure for the ionic
compound Ca(ClO2)2?
7.
a.
b.
c.
d.
e.
The compound expected when chlorine reacts with aluminum is
Al2Cl3
Al3Cl2
AlCl3
Al3Cl
AlCl2
22
8. What ions would you find in solution if potassium perchlorate was
dissolved in water?
a. KCl, O2
b. K+, Cl-, O-2
c. KCl, O-2
d. K+, ClO4e. K+, Cl-, O-2
9.
a.
b.
c.
d.
e.
Which one of the following is correct?
KClO3, potassium perchlorate
CuO, copper oxide
Al3(SO3)2, aluminum sulfate
MgPO4, magnesium phosphate
Na2Cr2O7, sodium dichromate
Cliff’s Ionic Bonding Answers
1. c
4. a
2. d
5. c
3. d
6. c
7. c
8. d
9. e
Princeton Review
Questions 1 – 4
(A) Metallic bonding
(B) Network covalent bonding
(C) Hydrogen bonding
(D) Ionic bonding
(E) London dispersion forces
1. Solids exhibiting this kind of bonding are excellent conductors of heat.
2. This kind of bonding is the reason that water is more dense than ice.
3. This kind of bonding exists between atoms with very different
electronegativities.
4. The stability exhibited by diamonds is due to this kind of bonding.
23
Questions 5 – 7
a.
b.
c.
d.
e.
CH4
NH3
NaCl
N2
H2
5. This substance undergoes ionic bonding.
6. This molecule contains two pi (π) bonds.
7. This substance undergoes hydrogen bonding.
Questions 8 – 10
(A) BF3
(B) CO2
(C) H2O
(D) CF4
(E) PH3
8. The central atom in this molecule forms sp2 hybrid orbitals
9. This molecule has a tetrahedral structure.
10. This molecule has a linear structure.
11. A liquid whose molecules are held together by which of the following
forces would be expected to have the lowest boiling point?
a. ionic bonds
b. London dispersion forces
c. Hydrogen bonds
d. Metallic bonds
e. Network bonds
12. Hydrogen bonding would be seen in a sample of which of the following
substances?
a. CH4
b. H2
c. H2O
d. HI
e. All of the above
24
13. Which of the following species down NOT have a tetrahedral structure?
a. CH4
b. NH4+
c. SF4
d. AlCl4e. CBr4
14. Which form of orbital hybridization can form molecules with shapes that
are either trigonal pyramidal or tetrahedral?
a. sp
b. sp2
c. sp3
d. dsp2
e. dsp3
15. The six carbon atoms in a benzene molecule are shown in different
resonance forms as three single bonds and three double bonds. If the
length of a single carbon-carbon bond is 154 pm and the length of a
double carbon-carbon bond is 133 pm, what length would be expected for
the carbon-carbon bonds in benzene?
a. 126 pm
b. 133 pm
c. 140 pm
d. 154 pm
e. 169 pm
25
16. Which of the following could be the Lewis structure for carbonate ion, CO3-2?
17. In which of the following species does the central atom NOT form sp2
hybrid orbitals?
a. SO2
b. BF3
c. NO3d. SO3
e. PCl3
26
18. A molecule whose central atom has d2sp3 hybridization can have which of
the following shapes?
I. tetrahedral
II. square pyramidal
III. square planar
a.
b.
c.
d.
e.
I only
III only
I and II only
II and III only
I, II, and III
19. Which of the following molecules will have a Lewis dot structure with
exactly one unshared electron pair on the central atom?
a. H2O
b. PH3
c. PCl5
d. CH2Cl2
e. BeCl2
20. Which of the following lists of species is in order of increasing boiling
point?
a. H2, N2, NH3
b. N2, NH3, H2
c. NH3, H2, N2
d. NH3, N2, H2
e. H2, NH3, N2
Princeton Review Answers
1. a
2. c
3. d
4. b
5. c
6. d
7. b
8. a
9. d
10. b
11. b
12. c
13. c
14. c
15. c
16. a
17. e
18. d
19. b
20. a
27
Princeton Review – Phase Changes
Questions 1-4 refer to the phase diagram below
1. At this point the substance represented by the phase diagram will be solely in
the solid phase.
2. This point represents a boiling point of the substance.
3. At his point, the substance represented by the phase diagram could be
undergoing sublimation.
4. At this point the substance represented by the phase diagram will be solely in
the liquid phase.
5. When a substance undergoes a phase change from liquid to solid, which of
the following will occur?
a. energy will be released by the substance because intermolecular
forces are being weakened
b. energy will be released by the substance because intermolecular
forces are being strengthened
c. energy will be absorbed by the substance because intermolecular
forces are being weakened
d. energy will be absorbed by the substance because intermolecular
forces are being strengthened
e. the energy of the substance will not be changed
28
6. Which of the following is true of a substance in the liquid phase.
a. its temperature must be less than 100 oC
b. its temperature must be greater than 0 oC
c. its temperature must be lower than that of the surrounding
atmosphere
d. its vapor pressure must be greater than the pressure of the
surrounding atmosphere
e. its vapor pressure must be lower than the pressure of the
surrounding atmosphere
Questions 7-10 are based on the phase diagram below
7. As pressure on the substance depicted in the diagram is increased at constant
temperature, which of the following phase changes could NOT occur?
I.
condensation
II.
melting
III.
freezing
a.
b.
c.
d.
e.
I only
II only
III only
I and II only
I and III only
29
8. At a temperature of 50 oC and a pressure of 0.2 atmospheres, the substance
depicted in the diagram is
a. in the gas phase
b. in the liquid phase
c. in the solid phase
d. at its triple point
e. at its critical point
9. Which of the following lists the three phases of the substance shown in the
diagram in order of increasing density at –5 oC?
a. solid, gas, liquid
b. solid, liquid, gas
c. gas, liquid, solid
d. gas, solid, liquid
e. liquid, solid, gas
10. When the temperature of the substance depicted in the diagram is decreased
from 10 oC to –10 oC at a constant pressure of 0.3 atmosphere, which phase
change will occur?
a. gas to liquid
b. liquid to solid
c. gas to solid
d. liquid to gas
e. solid to liquid
11. Which of the following processes can occur when the temperature of a
substance is increased at constant pressure?
I. sublimation
II. melting
III. boiling
a.
b.
c.
d.
e.
I only
II only
I and II
II and III
I, II and III
30
12. The temperature above which gas molecules become too energetic to form a
true liquid, no matter what the pressure, is called the
a. melting point
b. critical point
c. boiling point
d. triple point
e. freezing point
Princeton Review Phase Change Answers
1. b
4. c
2. d
5. b
3. a
6. e
7. c
8. a
9. d
10. b
11. e
12. b
Fast Track to a 5 – Liquids and Solids
1. Water has a higher capillary action than mercury due to
a. higher dipole-dipole forces between the water molecules
b. strong cohesive forces within water
c. very significant induced intermolecular attractions
d. weak adhesive forces in water
e. strong cohesive forces in water which work with strong adhesive forces
2. The Clausius-Clapeyron equation indicates that
I. the greater the vapor pressure, the higher the entropy of vaporization
II. the higher the heat of vaporization, the steeper the slope of lnP vs 1/T
III. the enthalpy of vaporization is equal to the slope of the vapor pressure vs
temperature
a.
b.
c.
d.
e.
I only
II only
III only
I and II only
I, II and III
3. Small drops of water tend to bead up because of
a. high capillary action
b. the shape of the meniscus
c. the resistance to increased surface area
d. low London dispersion forces
e. weak covalent bonds
31
4. The vapor pressure increases in a predictable order as shown as
a. methane<ethanol<diethyl ether<neon
b. neon<methane<diethyl ether<ethanol
c. ethanol<diethyl ether<methane<neon
d. diethyl ether<ethanol<methane<neon
e. diethyl ether<ethanol<neon<methane
5. Several liquids are compared by adding them to a series of 50-mL graduated
cylinders, then dropping a steel ball of uniform size and mass into each. The
time required for the ball to reach the bottom of the cylinder is noted. This is
a method used to compare the differences in a property of liquids known as
a. surface tension
b. buoyancy
c. capillary action
d. viscosity
e. surface contraction
6. The properties of solids vary with their bonding. An example of this is
shown by
a. ionic solids with strong electrostatic attractions called ionic bonds,
which have high melting temperatures
b. molecular solids with high intermolecular forces which have high
melting temperatures
c. ionic solids with highly mobile ions which have high conductance
d. amorphous solids with strong London dispersion forces and high
vapor pressure
e. network solids with low melting temperatures due to strong covalent
bonds
7. As you go down the noble gas family on the periodic table, the boiling
temperature increases. This trend is due mainly to
a. an increase in hydrogen bonding
b. a decrease in dipole-dipole forces
c. the lower atomic masses as you go down the family
d. an increase in London dispersion forces
e. an increase in lattice energy
32
8. Carbon dioxide and silicon dioxide have properties which differ dramatically.
This is due
a. to the hardness of silica compounds
b. the size difference of carbon and silicon, resulting in less effective
overlap with the smaller orbits of oxygen
c. shared CO2 and CO4 tetrahedra
d. the formation of a glass when silicates are heated
e. the repeating sigma bonds formed in carbon dioxide
9. This question refers to the phase diagram shown. Select the true statement.
a. point E represents both critical
temperature and critical pressure
b. moving from point A to point F is
sublimation
c. point C represents both solid and
vapor states
d. point B represents both solid and
vapor states
e. point D represents a point where,
no matter how much pressure is
exerted, a liquid cannot form
10. The densities of certain compounds are greater as liquids than as solids. This
means that increasing the pressure will result in
a. a solid becoming a liquid
b. a liquid becoming a solid
c. lowering of the critical temperature
d. elevation of the freezing temperature
e. lowering of the triple point
Fast Track to a 5 – Liquids and Solids Answers
1. e
4. c
7. d
2. b
5. d
8. b
3. c
6. a
9. b
10. a
33
Fast Track to a Five – Bonding, Structure and Organic Chemistry
1. The compound most likely to be ionic is
a. KF
b. CCl4
c. CO2
d. ICl
e. CS2
2. Ranking the ions S2-, Ca2+, K+, Cl- from smallest to largest gives the order as
a. S2-, Cl-, K+, Ca2+
b. Ca2+, K+, Cl-, S2c. K+, Ca2+, Cl-, S2d. Cl-, S2-, K+, Ca2+
e. Ca2+, K+, S-2, Cl3. The type of bonding within a water molecule is
a. ionic bonding
b. polar covalent bonding
c. nonpolar covalent
d. metallic bonding
e. hydrogen bonding
4. Dinitrogen monoxide has two double bonds. The general structure is
N=N=O. The formal charge on the oxygen is
a. zero
b. positive one
c. positive two
d. negative one
e. negative two
5. The Lewis structure of which molecule requires resonance structures?
a. MgCl2
b. PCl5
c. SiO2
d. SO2
e. OCl2
34
6. The predicted geometry of PH3, according to VSEPR, is
a. linear
b. bent
c. trigonal pyramidal
d. tetrahedral
e. trigonal planar
7. Rank the following from lowest to highest boiling temperature:
I.
ethane
II.
ethanol
III.
chloro ethane
a.
b.
c.
d.
e.
I < II < III
II < III < I
III < II < I
III < I < II
I < III < II
8. The total number of lone pairs in PCl3 is
a. 1
b. 8
c. 10
d. 12
e. 14
9. The Lewis structure for carbon dioxide is
a. :C=O-O:
b. :C=O-O:
c.
:C-O-O
d. :O=C=O:
e.
:O=C=O:
35
10. Which of the following molecules has a net dipole (dipole moment)?
I.
CO2
II.
SO3
III.
CCl4
IV.
PF3
a.
b.
c.
d.
e.
I and II only
II and III only
III only
IV only
II, III, and IV
Fast Track to a Five – Bonding, Structure and Organic Chemistry Answers
1. a
4. a
7. e
10. d
2. b
5. d
8. c
3. b
6. c
9. d
Kaplan: Intermolecular Forces and the Condensed Phases of Matter
11. Which is true?
a. London forces are also called dispersion forces
b. London forces occur between permanent dipoles
c. Hydrogen bonds are weaker than dipole-dipole forces
d. Hydrogen bonds occur only between nonpolar molecules
e. Dispersion forces account for the high boiling point of water
12. Which hydrocarbon has the strongest dispersion forces between its
molecules?
a. CH4
b. C2H6
c. C5H12
d. C6H6
e. C8H18
36
13. Which best explains why water is a liquid at ordinary earth conditions while
all other molecules with comparable molecular weights on earth are gases?
Water:
a. is polar
b. exhibits hydrogen bonding
c. is the most common liquid on earth
d. has extremely strong dispersion forces
e. takes the shape of its container but has a fixed volume
14. Why is it possible to float a pin on the surface of water?
a. the surface tension of the water is very low
b. the density of the pin is less than that of the water surface tension
c. only the sharp tip of the pin will break the surface tension of the water
d. the surface molecules of the water change bonding as they dry out
e. the mass of the pin does not exert enough force to increase the surface
area needed to sink it
15. What type of solid has a high melting point, does not conduct heat and
electricity in either the solid or liquid state, and does not dissolve in water or
organic solvents?
a. ionic
b. network
c. molecular
d. amorphous
e. high viscosity solution
16. What statement correctly justifies two correct reasons why MgS has a higher
melting point than CsI?
a. Mg has higher metallic character and S is a more reactive nonmetal
b. MgS has a greater ionic charge and its ions are smaller
c. MgS has larger dispersion forces and a less structured crystal lattice
d. MgS has greater electron mobility and forms an amorphous solid
e. MgS has a high solubility in water and forms solutions with a high
electrical conductivity
37
17. Select the choice that correctly matches the Structural Unit, the Attractive
Force between them, and an example of the type of solid.
Structural Unit
a. molecules
b. diatomic molecules
c. metallic anions
d. metallic cations
e. oppositely charged
anions and cations
Attractive Force
Covalent bonds
Covalent bonds
Electrostatic forces
Covalently bonded ions
Electrostatic forces
Example
Iodine
Helium
Gold
Diamond
Sodium
chloride
18. Which causes in increase in vapor pressure?
a. increased pressure
b. decreased pressure
c. increased intermolecular attractions
d. increased temperature
e. decreased temperature
19. When a solid melts, the temperature of the solid:
a. first decreases, then increases after all the solid melts
b. remains the same and the potential energy increases
c. decreases due to a decrease in average molecular kinetic energy
d. increases at a characteristic slope related to the strength of attractive forces
e. increases at a positive rate when there is a density increase, and at a rate
slope when there is a density decrease
20. Which can be used to predict the strength of the intermolecular attractions
between molecules?
I.
the viscosity of a liquid
II.
the pressure on a liquid
III.
the molar mass of a liquid
IV.
the boiling point of a liquid
a.
b.
c.
d.
e.
I only
I and IV only
II and III only
I, II and IV only
II, III, and IV only
38
Kaplan: Intermolecular Forces and the Condensed Phases of Matter Answers
1. a
4. c
7. e
10. b
2. e
5. b
8. d
3. b
6. b
9. b
39