ch9 and 10 practice test
1.
Which of the following covalent bonds is the most polar (highest percent ionic character)?
A. Al •I
2.
B. sp2
D. Si •Cl
E. Si •P
C. sp3
D. sp3d
E. sp3d2
Which of the following solids would have the lowest melting point?
A. KI
4.
C. Al •Cl
What is the hybridization of the central atom in ClO3– ?
A. sp
3.
B. Si •I
B. KBr
C. KCl
D. KF
Estimate the enthalpy change, ΔH, for the reaction 2CO + O2 → 2CO2 given the
following bond energies.
BE(C≡O) = 1074 kJ/mol
BE(O=O) = 499 kJ/mol
BE(C=O) = 802 kJ/mol
A. +2380 kJ
5.
D. NCl3
E. Cl2
B. 2
C. 3
D. 5
E. 8
B. Ga
C. Si
D. Ba
E. Pb
B. Cs
C. P
D. As
E. Ge
B. OF2
C. CH3Cl
D. H2O
E. BeCl2
The geometry of the ClF3 molecule is best described as:
A.
B.
C.
D.
E.
11.
C. ICl
Which one of the following molecules is nonpolar?
A. NH3
10.
B. AsCl5
Which of the atoms listed below is the most electronegative?
A. Li
9.
E. -744 kJ
Which of the elements listed below has the greatest electronegativity?
A. Mg
8.
D. -561 kJ
How many covalent bonds will a nitrogen atom usually form?
A. 1
7.
C. +1949 kJ
Which one of the following molecules has an atom with an expanded octet?
A. HCl
6.
B. +744 kJ
distorted tetrahedron
trigonal planar
tetrahedral
T-shaped
trigonal pyramidal
According to the VSEPR, theory the geometry of the atoms in the carbonate ion, CO32– is
A.
B.
C.
D.
E.
square planar.
tetrahedral.
pyramidal.
trigonal planar.
octahedral.
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ch9 and 10 practice test
12. Which one of the following compounds does not follow the octet rule?
A. NF3
13.
C. PF5
D. AsH3
E. HCl
The bond between which of the following pairs of atoms would be the least polar (lowest
percent ionic character)?
A. C •Cl
14.
B. CF4
B. C •C
C. C •H
D. O •C
E. N •C
The total number of bonding electrons in a molecule of formaldehyde (H2CO) is
A. 3
B. 4
C. 6
D. 8
E. 18
15. A nonpolar covalent bond (pure covalent) would form between which one of the following
pairs of atoms?
A. Na •Cl
16.
B. H •Cl
C. Li •Br
D. Se •Br
E. Br •Br
D. sp3d
E. sp3d2
What is the hybridization on the central atom in NO3– ?
A. sp
B. sp2
C. sp3
18. The Lewis structure for a chlorate ion, ClO3• should show ____ single bond(s), ____
double bond(s), and ____ lone pair(s).
A. 2, 1, 10
19.
B. 8
C. 9
D. 10
E. 13
B. XeF4
C. NF3
D. SF6
E. PF5
linear.
trigonal planar.
tetrahedral.
bent.
trigonal pyramidal.
Predict the molecular geometry and polarity of the SO2 molecule.
A.
B.
C.
D.
E.
23.
E. 2, 1, 10
The geometry of the CS2 molecule is best described as
A.
B.
C.
D.
E.
22.
D. 3, 0, 10
According to VSEPR theory, which one of the following molecules should be trigonal
bipyramidal?
A. SF4
21.
C. 2, 1, 8
Each of the three resonance structures of NO3• has how many lone pairs of electrons?
A. 7
20.
B. 3, 0, 9
linear, polar
linear, nonpolar
bent, polar
bent, nonpolar
None of the above.
Which one of the following is most likely to be a covalent compound?
A. Rb2S
B. SrCl2
C. CS2
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D. CaO
E. MgI2
ch9 and 10 practice test
24.
The electron dot formula for AsCl3 shows: (complete)
A.
B.
C.
D.
E.
25.
a total of 84 electron dots
three single bonds and 10 lone pairs
two single bonds, one double bond, and 9 lone pairs
one single bond, two double bonds, and 8 lone pairs
three single bonds and one lone pair
Which of the following is a useful guideline for the application of formal charges? For
neutral molecules:
A. a Lewis structure in which there are no formal charges is preferred.
B. Lewis structures with large formal charges (+2,+3 and/or -2,-3) are preferred.
C. the preferred Lewis structure is one in which positive formal charges are on the most
electronegative atoms.
26.
Which of the following pairs of elements would be most likely to form an ionic compound?
A.
B.
C.
D.
E.
27.
Cl and I
Al and K
Cl and Mg
C and S
Al and Mg
Which molecule has a Lewis structure that does not obey the octet rule?
A. N2O
28.
B. CS2
C. PH3
D. CCl4
E. NO2
Use bond energies to estimate the enthalpy change (ΔH) for the reaction
CH4 + Cl2 → CH3Cl + HCl
BE(C •H) = 1074 kJ/mol
BE(C •Cl) = 499 kJ/mol
BE(H •Cl) = 802 kJ/mol
BE(Cl •Cl) = 1074 kJ/mol
A. -103 kJ
29.
B. -109 kJ
C. +275 kJ
D. +109 kJ
E. +103 kJ
The Lewis dot symbol for the Ca 2+ ion is
A.
Ca
B. • Ca•
C.
Ca
2+
2+
D. Ca2+
E. Ca
30.
Which of the following solids would have the highest melting point?
A. NaF
B. NaCl
C. NaBr
Page 3
D. NaI
ch9 and 10 practice test
32.
Predict the geometry and polarity of the CS2 molecule.
A.
B.
C.
D.
E.
33.
The F –Cl –F bond angles in ClF3 are
A.
B.
C.
D.
E.
34.
linear, polar
linear, nonpolar
tetrahedral, nonpolar
bent, nonpolar
bent, polar
90° only.
109.5° only.
120° only.
180° only.
90° and 180°.
In which one of the following molecules is the central atom sp2 hybridized?
A. SO2
35.
B. N2O
C. BeCl2
D. NF3
E. PF5
Which one of the following molecules has an atom with an incomplete octet?
A. NF3
B. H2O
C. AsCl3
D. GeH4
E. BF3
36. The hybridization of the phosphorus atom in the cation PH2+ is:
a)
b)
c)
d)
e)
sp2
sp3
dsp
sp
none of these
37. In the molecule C2H4 the valence orbitals of the carbon atoms are assumed to be
a)
b)
c)
d)
e)
not hybridized.
sp hybridized.
sp2 hybridized.
sp3 hybridized.
dsp hybridized.
38. Which of the following statements is (are) incorrect?
I.
II.
III.
IV.
a)
b)
c)
d)
e)
The hybridization of boron in BF3 is sp2.
The molecule XeF4 is nonpolar.
The bond order of N2 is three.
The molecule HCN has two pi bonds and two sigma bonds.
All four statements are correct.
II is incorrect.
I and IV are incorrect.
II and III are incorrect.
II, III, and IV are incorrect.
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ch9 and 10 practice test
39. Atoms which are sp2 hybridized form ____ pi bond(s).
a)
b)
c)
d)
e)
0
1
2
3
4
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ch9 and 10 practice test
40. The hybridization of the central atom in XeF5+ is:
a)
b)
c)
d)
e)
sp
sp2
sp3
dsp3
d2sp3
41. The hybridization of the central atom in ClF2+ is:
a)
b)
c)
d)
e)
sp
sp2
sp3
dsp3
d2sp3
42. The hybridization of the central atom in I3- is:
a)
b)
c)
d)
e)
sp
sp2
sp3
dsp3
d2sp3
43. The hybridization of the central atom in O3 is:
a)
b)
c)
d)
e)
sp
sp2
sp3
dsp3
d2sp3
44. Which of the following molecules contains a central atom with sp2 hybridization?
a)
b)
c)
Page 6
ch9 and 10 practice test
d)
e)
45. What hybridization is predicted for the nitrogen atom in the NO3– ion?
a)
b)
c)
d)
e)
sp2
sp3
sp3d
sp3d2
none of these
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ch9 and 10 practice test
46. Which of the following does not contain at least one pi bond?
a)
H2CO
b)
CO2
c)
C 2 H4
d)
C 3 H8
e)
All of these (a-d) contain at least one pi bond.
47. Consider the following Lewis structure
Which statement about the molecule is false?
a)
b)
c)
d)
e)
There are 10 sigma and 2 pi bonds.
C–2 is sp2 hybridized with bond angles of 120°.
Oxygen is sp3 hybridized.
This molecule contains 28 valence electrons.
There are some H–C–H bond angles of about 109° in the molecule.
Page 8
ch9 and 10 practice test
48. Consider the following Lewis structure:
What is the hybridization of the
oxygen atom and carbon atoms 1, 2, and 4, respectively?
Option 1:
Option 2:
Option 3:
Option 4:
Option 5:
a)
b)
c)
d)
e)
O
C–1
3
sp3
sp
sp3
sp
sp
sp2
sp2
sp3
sp
sp3
Option 1
Option 2
Option 3
Option 4
Option 5
C–2
sp
sp
sp
sp2
sp2
C–4
sp2
sp
sp2
sp3
sp
49. The following statements concern molecules that require resonance. Which is true?
a)
b)
c)
d)
e)
The pi bonding is most clearly delocalized.
The sigma bonding is most clearly delocalized.
Both the sigma and pi bonding are delocalized.
The benzene molecule is best described by the MO theory.
The benzene molecule is best described by the localized electron model.
50. Consider the benzene molecule. Which of the following statements about the molecule is
false?
a)
b)
c)
d)
e)
All six C ⎯ C bonds are known to be equivalent.
Each carbon atom is sp2 hybridized.
The localized electron model must invoke resonance to account for the six equal
C ⎯ C bonds.
It has delocalized pi bonding in the molecule.
The pi bonds of carbon involve sp2 orbitals.
Page 9
ch9 and 10 practice test
Answer Key for Test "ch 9 and 10 test.tst", 2/17/2010
No. in
Q-Bank
9-33
10-32
9-20
9-66
9-63
9-50
9-28
9-25
10-18
10-6
10-7
9-59
9-37
9-44
9-31
10-29
9-23
9-47
9-56
10-9
10-5
10-23
9-5
9-43
9-51
9-4
9-64
9-69
9-14
9-18
9-22
10-24
10-16
10-30
9-62
No. on
Test
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
Correct
Answer
C
C
A
D
B
C
C
C
E
D
D
C
B
D
E
B
D
D
B
E
A
C
C
B
A
C
E
A
D
A
E
B
E
A
E
36.ANS:a) sp2
PAGE: 9.1
37ANS: c)
sp2 hybridized.
PAGE: 9.1
38ANS: a)
All four statements are correct.
PAGE: 9.1
39ANS:b)
1
PAGE: 9.1
40ANS: e) d2sp3
PAGE: 9.1
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ch9 and 10 practice test
41ANS: c)
sp3
PAGE: 9.1
42ANS:d)
dsp3
PAGE: 9.1
43ANS: e)
sp2
PAGE: 9.1
ANS:
b)
PAGE: 9.1
44
45ANS: a)
sp2
PAGE: 9.1
46ANS:d)
C 3 H8
PAGE: 9.1
47ANS: c)
Oxygen is sp3 hybridized.
PAGE: 9.1
48ANS: a)
Option 1
PAGE: 9.1
49ANS: a)
The pi bonding is most clearly delocalized.
PAGE: 9.5
50ANS: e)
The pi bonds of carbon involve sp2 orbitals.
PAGE: 9.5
Page 11