Chapter 9: Covalent Bonding: Orbitals
1. The hybridization of the carbon atom in the cation CH3+ is:
A)
sp2
B)
sp3
C)
dsp
D)
sp
E)
none of these
2. 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
3. Atoms that are sp2 hybridized form ____ pi bond(s).
A)
0
B)
1
C)
2
D)
3
E)
4
4. The hybridization of the central atom in XeF5+ is:
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
5. The hybridization of the central atom in ClF2+ is:
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
6. The hybridization of the central atom in I3– is:
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
7. The hybridization of the central atom in O3 is:
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
8. Which of the following molecules contains a central atom with sp2 hybridization?
A)
B)
C)
D)
E)
9. What hybridization is predicted for the nitrogen atom in the NO3– ion?
A)
sp2
B)
sp3
C)
dsp3
D)
d2sp3
E)
none of these
10. Which of the following does not contain at least one pi bond?
A)
H2CO
B)
CO2
C)
C2H4
D)
C2H6
E)
All of the above (A-D) contain at least one pi bond.
11. 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.
12. Which statement about N2 is false?
A)
It is a gas at room temperature.
B)
The oxidation state is +3 on one N and –3 on the other.
C)
It has one sigma and two pi bonds between the two atoms.
D)
It can combine with H2 to form NH3.
E)
It has two pairs of nonbonding electrons.
13. Consider the following Lewis structure:
What is the hybridization of the atoms O, C-1, C-2, and C-4?
A)
sp3 sp3 sp sp2
B)
sp sp3 sp sp
C)
sp sp2 sp sp2
D)
sp2 sp3 sp2 sp3
E)
sp3 sp sp sp2
O C–1 C–2 C–4
Consider the molecule and the following hybridization choices:
14. What is the hybridization of the carbon atom that is double-bonded to oxygen?
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
15. What is the hybridization of the carbon atom that is bonded to chlorine?
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
16. What is the hybridization of the nitrogen atom?
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
17. What is the hybridization of the oxygen atom?
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
18. The hybridization of I in IF4– is
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
19. The hybridization of Cl in ClF2+ is
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
20. Consider the molecule:
Specify the hybridization of each carbon atom.
C-1
C-2
C-3
C-4
C-5
A)
sp2 sp2 sp2 sp3 sp
B)
sp2 sp2 sp2 sp3 sp3
C)
sp2 sp2 sp3 sp3 sp2
D)
sp2 sp2 sp3 sp3 sp3
E)
sp2 sp sp sp2 sp
21. The hybridization of the central atom, Al, in AlBr3 is
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
22. The hybridization of Se in SeF6 is
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
23. The hybridization of Br in BrF3 is
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
24. The hybridization of the lead atom in PbCl4 is
A)
dsp2
B)
sp2
C)
d2sp3
D)
dsp3
E)
none of these
25. The hybridization of the central atom in NO3– is
A)
p3
B)
sp2
C)
sp3
D)
sp
E)
dsp2
Tetracyanoethylene has the skeleton shown below:
From its Lewis structure determine the following:
26. How many sigma and pi bonds are in the molecule?
A)
4 sigma and 5 pi
B)
6 sigma and 8 pi
C)
9 sigma and 8 pi
D)
9 sigma and 9 pi
E)
5 sigma and 8 pi
27. How many nonbonded electron pairs are in the molecule?
A)
0
B)
2
C)
4
D)
5
E)
8
28. How many of the atoms are sp2 hybridized?
A)
2
B)
4
C)
6
D)
8
E)
10
29. How many of the atoms are sp hybridized?
A)
2
B)
4
C)
6
D)
8
E)
10
30. In which of the compounds below is there more than one kind of hybridization (sp, sp2, sp3)
for carbon?
I.
CH3CH2CH2CH3
II.
CH3CH = CHCH3
III.
CH2 = CH – CH = CH2
IV.
H – C C – H
A)
II and III
B)
II only
C)
III and IV
D)
I, II, and III
E)
III only
31. Complete the Lewis structure for the following molecule:
This molecule has __________ sigma and __________ pi bonds.
A)
4, 5
B)
6, 3
C)
11, 5
D)
13, 2
E)
13, 3
32. Which of the following substances contains two pi bonds?
A)
C2H4
B)
C3H8
C)
C2H2
D)
C2H6
E)
CH4
33. Consider the molecule C2H4. The hybridization of each C atom is
A)
sp
B)
sp2
C)
sp3
D)
dsp3
E)
d2sp3
34. A (pi) bond is the result of the
A)
overlap of two s orbitals
B)
overlap of an s orbital and a p orbital
C)
overlap of two p orbitals along their axes
D)
sidewise overlap of two parallel p orbitals
E)
sidewise overlap of two s orbitals
35. When a carbon atom has sp3 hybridization, it has
A)
four bonds
B)
three bonds and one bond
C)
two bonds and two bonds
D)
one bond and three bonds
E)
four bonds
Consider the skeletal structure shown below:
N—C—C—N
Draw the Lewis structure and answer the following:
36. How many of the atoms are sp hybridized?
A)
0
B)
1
C)
2
D)
3
E)
4
37. How many pi bonds does the molecule contain?
A)
0
B)
2
C)
4
D)
6
E)
7
Use the molecules below to answer the next three questions.
38. Which molecule(s) have p orbitals that share an electron pair to create bonding?
A)
I
B)
II
C)
III
D)
all of the above
E)
none of the above
39. Which molecule(s) have at least one carbon atom that is sp hybridized?
A)
I
B)
II
C)
III
D)
all of the above
E)
none of the above
40. Which molecule(s) have equivalent C–C bonds throughout the molecule?
A)
I
B)
II
C)
III
D)
all of the above
E)
none of the above
41. Whenever a set of equivalent tetrahedral atomic orbitals is required, an atom will adopt a set
of sp3 orbitals.
42. The hybridization of the B in BH3 is sp3.
43. The hybridization of a molecule is measured to determine the shape of the molecule.
44. Which of the following statements is true?
A)
Electrons are never found in an antibonding MO.
B)
All antibonding MOs are higher in energy than the atomic orbitals of which they
are composed.
C)
Antibonding MOs have electron density mainly outside the space between the two
nuclei.
D)
None of the above is true.
E)
Two of the above statements are true.
45. 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.
46. Which of the following molecules contains the shortest C–C bond?
A)
C2H2
B)
C2H4
C)
C2H6
D)
C2Cl4
E)
b and d
47. The electron configuration of a particular diatomic species is (2s)2(*2s)2(2p)2(2p)4(*2p)2.
What is the bond order for this species?
A)
3.5
B)
3
C)
2.5
D)
2
E)
1.5
48. What is the bond order of He2+?
A)
0
B)
C)
1
D)
E)
2
49. If four orbitals on one atom overlap four orbitals on a second atom, how many molecular
orbitals will form?
A)
1
B)
4
C)
8
D)
16
E)
none of these
50. Larger bond order means greater bond strength.
51. When an electron pair is shared in the area centered on a line joining the atoms, a (sigma)
bond is formed.
52. As the bond order of a bond increases, the bond energy ______ and the bond length ______.
A)
increases, increases
B)
decreases, decreases
C)
increases, decreases
D)
decreases, increases
E)
More information is needed to answer this question.
53. When comparing Be2 and H2:
I.
Be2 is more stable because it contains both bonding and antibonding valence
electrons.
II.
H2 has a higher bond order than Be2.
III.
H2 is more stable because it only contains 1s electrons.
IV.
H2 is more stable because it is diamagnetic, whereas Be2 is paramagnetic.
A)
I, II
B)
III only
C)
II, III
D)
II, III, IV
E)
III, IV
54. If a molecule demonstrates paramagnetism, then :
I.
The substance can have both paired and unpaired electrons.
II.
The bond order is not a whole number.
III.
It can be determined by drawing a Lewis structure.
IV.
It must be an ion.
A)
I, II
B)
I, II, IV
C)
II, III
D)
I only
E)
All of the above are correct.
55. For which of the following diatomic molecules would the bond order become greater if an
electron is removed (i.e., if the molecule is converted to the positive ion in its ground state)?
A)
B2
B)
C2
C)
P2
D)
F2
E)
Na2
56. The configuration (2s)2(2s*)2(2py)1(2px)1 is the molecular orbital description for the
ground state of
A)
Li2+
B)
Be2
C)
B2
D)
B22–
E)
C2
57. Which of the following species is paramagnetic?
A)
C2
B)
O2
C)
F2
D)
Li2
E)
none of these
58. Which of the following species has the largest dissociation energy?
A)
O2
B)
O2–