Practice Test Ch 8 & 9 (pg 1 of 6)
1.
The correct Lewis symbol for ground state for atomic
carbon is
a.
2.
Bonding & Geometry
b.
8.
c.
Which of the following is the correct Lewis structure for
SOCl2? (Consider formal charge.)
a.
b.
d.
e.
Using the picture below, what process corresponds to the
lattice energy?
d.
9.
b.
e.
a.
d.
c.
3.
4.
5.
6.
7.
Which of the atoms below is least likely to violate the
octet rule by having less than 8 an octet?
a. Be
b. P
c. S
d. B
e. F
How many valence electrons are shown in the Lewis
structure of perchlorate ion, ClO4-1?
a. 30
b. 31
c. 32
d. 50
e. 51
Which of the following bonds is most polar?
a. N – Cl
b. C – N
c. S – S
d. Br – Br
e. S – O
What is the size of the C–C–O bond angle in
a. 90
b. 109.5
c. 120
d. <120
e. > 120
Which of the following is an exception to the octet rule?
a. NO2
b. H2O
c. O3
d. CCl4
e. none of these
c.
e.
Which one of the following molecules is a polar
molecule?
a. Cl2
b. CO2
c. NF3
d. CCl4
e. H2S
10. Which of the following molecular shapes has six atoms
joined to a central atom?
a. octahedral
b. linear
c. trigonal bipyramidal
d. tetrahedral
e. planar triangular
11. Which molecular shape has bond angles which are not all
the same?
a. linear
b. planar triangular
c. tetrahedral
d. trigonal bipyramidal
e. octahedral
12. What is the geometry of the electron domains in the
molecule XeF2
a. linear
b. planar triangular
c. tetrahedral
d. trigonal bipyramidal
e. octahedral
13. The molecule BrF3 has how many lone pairs of electrons
on the central atom?
a. 0
b. 1
c. 2
d. 3
e. 4
14. What is the geometrical arrangement of electron domains
in H2O?
a. linear
b. trigonal bipyramidal
c. bent
d. tetrahedral
e. octahedral
Practice Test Ch 8 & 9 (pg 2 of 6)
Bonding & Geometry
15. What is the shape of BrI3?
a. square planar
b. pyramidal
c. T-shaped
d. bent
e. distorted tetrahedral
16. What type of hybridization is associated with a square
planar molecular shape?
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
17. What is the shape of the IF4-1 ion?
a. square planar
b. octahedral
c. tetrahedral
d. T-shaped
e. square pyramidal
18. Which of the following is a polar species?
a. CO2
b. PCl5
c. ICl2-1
d. TeCl4
e. CCl4
19. Among those listed below, which element will have the
strongest tendency to form double bonds?
a. Br
b. B
c. F
d. O
e. Mg
20. Which hybridization is associated with 3 domains?
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
21. The molecule SF4 has how many electron domains on the
central atom?
a. 2
b. 3
c. 4
d. 5
e. 6
22. What is the hybridization of Br in BrF5?
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
23. What shape for electron pairs is associated with sp3
hybridization?
a. linear
b. tetrahedral
c. square planar
d. octahedral
e. trigonal planar
24. What hybridization is predicted for phosphorus in the
PCl3 molecule?
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
25. A double bond contains ___ sigma bond(s) and ___ pi
bond(s).
a. 0, 2
b. 1, 2
c. 2, 0
d. 1, 1
e. 0, 1
26. What angle exists between domains in an octahedral
structure?
a. 90.0°
b. 120.0°
c. 180.0°
d. 78.5°
e. 109.5°
27. Which of the following elements is most likely to display
sp3d hybridization?
a. oxygen
b. carbon
c. nitrogen
d. boron
e. phosphorus
28. How many sigma (σ) and pi (π) bonds are in a carbon
dioxide molecule?
a. four σ and zero π
b. two σ and four π
c. three σ and two π
d. one σ and three π
e. two σ and two π
29. What is the hybridization of the oxygen atoms in CH3OH
and CO2, respectively?
a. sp3, sp3
b. sp2, sp2
c. sp3, sp2
d. sp3, sp
e. sp2, sp3
Practice Test Ch 8 & 9 (pg 3 of 6)
Bonding & Geometry
30. All of the following species contain two π-bonds
EXCEPT
a. SCN-1
b. OCS
c. CO
d. NO -1
e. H2CCO
36. Of the following molecules, which has the largest dipole
moment?
a. NH3
b. CO2
c. OF2
d. H2O
e. CF4
31. How many unshared pair of electrons on the central atom
in the molecule, XeF2?
a. 1
b. 2
c. 3
d. 4
e. 5
37. The molecular geometry of SF4 is
a. see-saw
b. t-shape
c. trigonal bipyramidal
d. octahedral
e. tetrahedron
32. Which of the following are true about BF3?
i. trigonal planar
ii. one unshared pair of electrons on B
iii. polar molecule
a. i only
b. i and ii only
c. i and iii only
d. ii and iii only
e. i, ii, and iii
33. Consider the chemical reaction below.
BF3 + NH3 → BF3NH3
During this chemical reaction, the geometry around the
boron atom changes from
a. trigonal pyramid to tetrahedral
b. trigonal planar to tetrahedral
c. trigonal planar to octahedral
d. trigonal pyramid to trigonal bipyramidal
e. actually its geometry doesn’t change at all
34. The melting point of CaS is higher than that of KCl.
Explanations for this observation include which of the
following?
I.
II.
III.
IV.
a.
b.
c.
d.
e.
Ca+2 is more positively charged than K+1
S-2 is more negatively charged than Cl-1
The S-2 ion is smaller than the Cl-1 ion.
The Ca+2 ion is smaller than the K+1 ion
II only
I, II, IV only
III and IV only
II and III only
I, II, III, and IV
35. Types of hybridization exhibited by the three C atoms in
propene, CH3CHCH2, include which of the following?
I. sp
a.
b.
c.
d.
e.
I only
III only
I and II only
II and III only
I, II, and III
II. sp2
III. sp3
38. In the molecule shown with the formula AF4 which
element could be in position A
a. S
b. O
c. Xe
d. P
e. It could be either a or b
39. In order to exhibit delocalized π bonding, a molecule must
have
a. at least two π bonds
b. at least two resonance structures
c. at least three σ bonds
d. at least four atoms
e. a and c are both true
40. In ozone, O3 the formal charge on the central atom is
a. 0
b. +1
c. -1
d. +2
e. -2
41. The Lewis structure of HCN shows that ______ has
_______ nonbonding electron pairs.
a. C, 1
b. N, 1
c. H, 1
d. N, 2
e. C, 2
42. According to the VSEPR model, the progressive decrease
in the bond angles in the series of molecules CH4, NH3
and H2O is best accounted for by the
a. increasing strength of bonds
b. decreasing size of the central atom
c. increasing the electronegativity of the central atom
d. increasing number of unshared pairs of electrons
e. decreasing repulsion between hydrogen atoms
43. The hybridization of the carbon atom in methane, CH4 is
a. sp
b. sp2
c. sp3
d. sp4
e. sp3d
Practice Test Ch 8 & 9 (pg 4 of 6)
Bonding & Geometry
For questions 44 - 51 refer to the following molecules.
(You might find it useful to sketch a Lewis structure for each
one.) More than one choice may be appropriate.
a. CO2
b. H2O
c. CH4
d. C2H4
e. PH3
f. None of the molecules above satisfy the statement.
44. The molecule whose central atom’s domains are
tetrahedral.
45. The molecule(s) with only one double bond.
46. The molecule with the largest dipole moment.
47. The molecule(s) that has trigonal pyramidal geometry.
48. The molecule(s) with at least one bond angle greater than
109.5°
49. The molecule(s) that exhibits “legitimate” resonance.
50. The molecule(s) with more than one pi bond.
51. The molecule(s) with no non-bonded electron pairs.
52. The central iodine atom in ICl4-1 has _______ unshared
electron pairs and ______ bonded electron pairs.
a. 3, 2
b. 3, 1
c. 1, 3
d. 1, 4
e. 2, 4
53. What is the maximum number of double bonds that a
single carbon atom can form?
a. 4
b. 3
c. 2
d. 1
e. 0
54. How many single covalent bonds must a silicon atom
form to have a complete octet of its valence electrons?
a. 4
b. 3
c. 2
d. 1
e. 0
55. The bond angles around the atoms 1, 2, and 3 in the
molecule below are approximately ______, _______, and
_______ respectively.
a. 90°, 90°, 90°
b. 120°, 120°, 90°
c. 120°, 120°, 109.5°
d. 109.5°, 120°, 109.5°
e. 109.5°, 90°, 120°
56. The hybridized orbitals around the C atom marked #2 in
the structure above are
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
57. Of the following, ________ can not accommodate more
than an octet of electrons.
a. P
b. Xe
c. N
d. S
e. I
58. A valid Lewis structure of _______ can not be drawn
without violation the octet rule.
a. PO4-3
b. SiF4
c. CF4
d. SeF4
e. NF3
59. The electron-domain geometry and molecular geometry
of iodine trichloride are ______ and ______ respectively.
a. trigonal planar, trigonal planar
b. tetrahedral, trigonal pyramidal
c. trigonal bipyramidal, T-shaped
d. octahedral, trigonal planar
e. T-shaped, trigonal planar
60. If the electron domain geometry of some sulfur-centered
compound is trigonal bipyramidal, then the hybridization
of the central sulfur atom must be _______
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2
61. There are _______ unhybridized p atomic orbitals on an
sp hybridized carbon atom
a. 0
b. 1
c. 2
d. 3
e. 4
62. If the hybridization of orbitals on the central atom of a
molecule is sp. The electron-domain geometry around this
central atom must be ________
a. octahedral
b. linear
c. trigonal planar
d. trigonal bipyramidal
e. tetrahedral
Practice Test Ch 8 & 9 (pg 5 of 6)
Bonding & Geometry
63. The shortest F-Xe-F bond angle in the XeF4 molecule is
about _______
a. 60°
b. 90°
c. 109.5°
d. 120°
e. 180°
64. When counting domains, a triple bond
a. Should not be counted as a domain
b. Depends on the geometry as to how many domains it
should be counted as
c. Should be counted as three domains
d. Should be counted as two domains due to the 2 π
bonds
e. Should be counted as only one domain
66. The electron-domain geometry and the molecular
geometry of a molecule of the general formula ABx will
be the same if
a. there are no unshared electron pairs on the central
atom
b. there is more than one central atom
c. x is greater than 4
d. x is less than 4
e. the octet rule is obeyed
67. Of the molecules below, only ______ is nonpolar.
a. BF3
b. NF3
c. IF3
d. PF3
e. BrF3
68. The molecular geometry of the H3O+1 ion is ______
a. linear
b. tetrahedral
c. bent
d. trigonal pyramidal
e. trigonal planar
65. A _______ covalent bond is the longest
a. single
b. double
c. triple
d. they are all the same length
e. nonpolar
69. Draw the Lewis structure for carbonate: CO3-2.
a.
What is the shape of the electron domains around the central carbon?
b.
What is the shape of the carbonate ion?
c.
What are the bond angles in carbonate?
d.
Does the carbonate ion exhibit resonance?
e.
Does delocalization occur? What does this term mean?
f.
Comment on the bond lengths in carbonate.
70. Bond enthalpy values can be used to calculate and estimation for ∆Hrx when the ∆Hf° values are not available for all the
compounds in the reaction. Use bond enthalpy values from the back of your ∆Hf tables to calculate the ∆Hrx for the reaction
below.
Do your work in the space below. Circle your final answer. Be sure and label it appropriately.
H2CNH + H2O → CH2O + NH3
Practice Test Ch 8 & 9 (pg 6 of 6)
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
69.
70.
Bonding & Geometry
ANSWERS
a
18. d
35. d
52. e
e
19. d
36. d
53. c
e
20. b
37. a
54. a
c
21. d
38. a
55. d
a
22. e
39. b
56. b
e
23. e
40. b
57. c
a
24. c
41. b
58. d
a
25. d
42. d
59. c
c
26. a
43. c
60. d
a
27. e
44.
61. c
d
28. e
45.
62. b
d
29. c
46.
63. b
c
30. d
47.
64. e
d
31. c
48.
65. a
c
32. b
49.
66. a
e
33. a
50.
67. a
a
34. b
51.
68. d
Carbonate ion
a.
trigonal planar
b.
trigonal planar
c.
120º
d.
yes, the double bond can be in any of the three possible locations
e.
yes, the electrons are delocalizes across all three bonds.
f.
the bond lengths will all be the same, somewhere between single and double length (closer to single)
∆H = -40 kJ
•
Drawing the Lewis structures will show a bond inventory will show
•
Bonds breaking: 1*C=N (615), 2*O-H (463), 1*N-H(391), 2*C-H(413)
•
Bonds forming: 1*C=O (799), 3*N-H (391), 2*C-H(413)
•
Note that you can cancel out 1*N-H and 2*C-H from breaking and forming for the net result of -40