Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 1. Which of the following is a correct Lewis structure for oxygen? a. b. c. d. e.
____ 2. Which of the following is a correct Lewis structure for C
2
H
6
O? a. b. c. d. Answers a and c are correct. e. Answers a, b, and c are correct.
____ 3. Which Lewis structure is possible for N
2
O? a. b. c. d. e.

____ 4. Which of the following is not a correct Lewis structure? a. NO b. NO
2
2
c. NO d. N
2
O e. All of the above are correct structures.
____ 5. What is the correct Lewis structure of SF
4
? a. b. c. d. e.
____ 6. Which of the following are correct resonance structures of SO
3
?

a. (1) and (5) b. (2) and (4) c. (1), (2), and (4) d. (2), (3) and (4) e. (1), (2), (4), and (5)
____ 7. How many lone pairs of electrons are on the sulfur atom in sulfite ion, SO
3
2-
? a. 0 b. 1 c. 2 d. 3 e. 4
____ 8. Formal charge is a. the absolute value of the charge on a polyatomic anion or cation. b. the difference between the number of lone pairs of electrons and shared pairs of electrons on any atom in a Lewis structure. c. the difference between the number of valence electrons and the number of protons in any given atom. d. equal to the number of valence electrons in a free atom minus the number of shared in covalent bonds. e. the difference between the number of valence electrons in a free atom and the number of electrons assigned to the atom in a Lewis structure.
____ 9. What is the formal charge on each atom in dichloromethane, CH
2
Cl
2
? a. C = 0, H = 0, Cl = 0 b. C = 0, H = -1, Cl = +1 c. C = 0, H = +1, Cl = -1 d. C = -2, H = +1, Cl = +1 e. C = +4, H = -1, Cl = -1
____ 10. Using formal charges and the octet rule, determine which Lewis structure of OCN
-
is most stable. a. b. c. d. e.

____ 11. Use VSEPR theory to predict the molecular geometry of BH
3
. a. triangular planar b. triangular pyramidal c. linear d. tetrahedral e. triangular bipyramidal
____ 12. Use VSEPR theory to predict the molecular geometry of ICl
3
. a. triangular planar b. triangular pyramidal c. triangular bipyramidal d. t-shaped e. octahedral
____ 13. Which of the following species have the same molecular geometry: CO
2
, H
2
O, BeCl
2
, and N
2
O? a. CO
2
and N
2
O only b. H
2
O and N
2
O only c. H
2
O and BeCl
2
only d. CO
2
and BeCl
2
only e. CO
2
, BeCl
2
, and N
2
O
____ 14. What are the bond angles in SF
6
? a. 90º and 180º b. 109.5º c. 120º d. 90º and 120º e. 180º
____ 15. What is the hybridization of the carbon atoms in benzene, C
6
H
6
? a. sp b. sp
2 c. sp
3 d. sp
3 d e. sp
3 d
2
____ 16. What hybridization change does the carbon atom undergo in the combustion of methane?
CH
4
( g ) + 2O
2
( g )
→
CO
2
( g ) + 2H
2
O( g ) a. sp
→
sp
2 b. sp 2 →
sp
3 c. sp d. sp
2
3 →
sp
→
sp e. none
____ 17. How many sigma and pi bonds are present in the following molecule?

a. 8 sigma bonds and 1 pi bond b. 8 sigma bonds and 2 pi bonds c. 10 sigma bonds and 2 pi bonds d. 11 sigma bonds and 2 pi bonds e. 11 sigma bonds and 1 pi bond
____ 18. Which element is the most electronegative? a. phosphorus b. silicon c. carbon d. nitrogen e. oxygen
____ 19. Which of the following compounds is expected to have the strongest ionic bonds? a. RbF b. NaF c. NaI d. CsBr e. CsI
____ 20. The central atom in XeF
4
is surrounded by a. 3 single bonds, 1 double bond, and no lone pairs of electrons. b. 2 single bonds, 2 double bonds, and no lone pairs of electrons. c. 3 single bonds, 1 double bond, and 1 lone pair of electrons. d. 4 single bonds, no double bonds, and no lone pairs of electrons. e. 4 single bonds, no double bonds, and 2 lone pairs of electrons.
____ 21. Which one of the following molecules has a dipole moment? a. CI
4 b. PF
5 c. NCl
3 d. SO
3 e. O
2
____ 22. Label the hybridization at C#1, C#2, C#3, and C#4 in the molecule.
C1 C2 C3 C4 a. sp sp sp
3
sp
3 b. sp sp sp
2
sp
3 d c. sp sp
2
sp
2
sp
2 d. sp
2
sp
2
sp
3
sp
3 e. sp
3
sp
3
sp
3
sp
3
____ 23. Which molecule is polar? a. BF
3 b. H
2
Se c. N
2 d. GeF
4

e. CO
2
____ 24. London forces exist a. for all molecules. b. only for molecules with nonpolar bonds. c. only for molecules with polar bonds. d. only for molecules with metallic bonds. e. only for molecules with hydrogen bonding.
____ 25. Which of the following interactions are present between CO
2
molecules?
I.
II.
London forces ion-dipole forces
III. hydrogen bonding
IV. dipole-dipole attractions a. I only b. II and III c. II only d. III only e. I and IV
____ 26. How many sigma (
σ
) bonds and pi (
π
) bonds are in the following molecule? a. five
σ
and two
π b. five
σ
and three
π c. five
σ
and five
π d. seven
σ
and two
π e. seven
σ
and three
π
____ 27. Which of the following characteristics apply to PCl
3
?
1. nonpolar molecule
2. polar bonds
3. trigonal-pyramidal molecular geometry
4. sp
2
hybridized a. 1 and 2 b. 2 and 3 c. 3 and 4 d. 1, 2, and 3 e. 1, 2, 3, and 4
____ 28. Which of the underlined atoms (C
1
, C
2
, N, and O) are sp
2
hybridized?

a. C
1
and C
2 b. C
1
, N, and O c. N and O d. O and C
2 e. O only
Molecular Orbital Theory
The following molecular orbital diagram may be used for the following problems. For oxygen and fluorine, the
σ
2p
orbital should be lower in energy than the
π
2p
. However, the diagram will still yield correct bond order and magnetic behavior for these molecules.
____ 29. According to molecular orbital theory, which of the following species is the most likely to exist? a. H
2
2b. He
2 c. Li
2 d. Li
2
2e. Be
2
____ 30. According to molecular orbital theory, what is the bond order of nitrogen, N
2
? a. 1 b. 3/2 c. 2 d. 5/2 e. 3

____ 31. Use molecular orbital theory to predict which species is paramagnetic. a. N
2 b. O
2 c. F
2 d. Li
2 e. H
2
____ 32. Refer to Molecular Orbital Theory. What is the molecular orbital configuration of N
2
? a. [core electrons] (
σ
2s
)
2 b. [core electrons] (
σ
2s
)
2 c. [core electrons] (
σ
2s d. [core electrons] (
σ
2s
)
2
) e. [core electrons] (
σ
2s
)
2
2
(
σ
*
2s
)
2
(
σ
*
2s
)
2
(
σ
*
2s
(
σ
*
2s
(
σ
*
2s
)
)
)
2
2
2
(
(
(
π
π
π
(
π
(
π
2p
2p
2p
2p
2p
)
2
(
)
2
(
σ
2p
)
2
(
)
)
4
4
(
σ
2p
(
σ
2p
)
2
)
4
2
(
σ
2p
)
)
2
(
π
*
2p
)
σ
*
2p
)
2
π
*
2p
)
2
(
π
*
2
2p
)
4

MULTIPLE CHOICE
1. ANS: A
2. ANS: D
3. ANS: B
4. ANS: C
5. ANS: B
6. ANS: B
7. ANS: B
8. ANS: E
9. ANS: A
10. ANS: B
11. ANS: A
12. ANS: D
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
13. ANS: E
14. ANS: A
15. ANS: B
16. ANS: C
PTS: 1
PTS: 1
PTS: 1
PTS: 1
17. ANS: E PTS: 1
18. ANS: E PTS: 1
OBJ: 08-7 Bond Properties: Bond Polarity and Electronegativity
19. ANS: B
20. ANS: E
21. ANS: C
PTS: 1
PTS: 1
PTS: 1
OBJ: 9.3 Bonding in Ionic Compounds
OBJ: 9.6 Exceptions to the Octet Rule
OBJ: 9.9 Molecular Polarity
22. ANS: B PTS: 1
OBJ: 09-3 Orbitals Consistent with Molecular Shapes: Hybridization
23. ANS: B PTS: 1 OBJ: 09-5 Molecular Polarity
24. ANS: A PTS: 1
OBJ: 09-6 Noncovalent Interactions and Forces Between Molecules
25. ANS: A PTS: 1
OBJ: 09-6 Noncovalent Interactions and Forces Between Molecules
26. ANS: E PTS: 1 OBJ: 10.2 Valence Bond Theory
27. ANS: B
28. ANS: A
29. ANS: C
30. ANS: E
31. ANS: B
32. ANS: C
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
PTS: 1
OBJ: 10.2 Valence Bond Theory
OBJ: 10.2 Valence Bond Theory
OBJ: 10.3 Molecular Orbital Theory
OBJ: 10.3 Molecular Orbital Theory
OBJ: 10.3 Molecular Orbital Theory
OBJ: 10.3 Molecular Orbital Theory