Chemistry: The Central Science, 12e (Brown et al.)
Chapter 9 Molecular Geometry and Bonding Theories
9.1 Multiple–Choice Questions
1) The basis of the VSEPR model of molecular bonding is __________.
A) regions of electron density on an atom will organize themselves so as to maximize s-character
B) regions of electron density in the valence shell of an atom will arrange themselves so as to maximize
overlap
C) atomic orbitals of the bonding atoms must overlap for a bond to form
D) electron domains in the valence shell of an atom will arrange themselves so as to minimize
repulsions
E) hybrid orbitals will form as necessary to, as closely as possible, achieve spherical symmetry
2) ClF3 has “T-shaped” geometry. There are __________ non-bonding domains in this molecule.
A) 0
B) 1
C) 2
D) 3
E) 4
3) The electron domain and molecular geometry of BrO2– is __________.
A) tetrahedral, trigonal planar
B) trigonal planar, trigonal planar
C) trigonal pyramidal, linear
D) tetrahedral, bent
E) trigonal pyramidal, seesaw
4) In counting the electron domains around the central atom in VSEPR theory, a __________ is not
included.
A) nonbonding pair of electrons
B) single covalent bond
C) core level electron pair
D) double covalent bond
E) triple covalent bond
5) The electron-domain geometry of __________ is tetrahedral.
A) CBr4
B) PH3
C) CCl2Br2
D) XeF4
E) all of the above except XeF4
6) The O-C-O bond angle in the CO32- ion is approximately __________.
A) 90°
B) 109.5°
C) 120°
D) 180°
E) 60°
7) Of the following species, __________ will have bond angles of 120°.
A) PH3
B) ClF3
C) NCl3
D) BCl3
E) All of these will have bond angles of 120°.
8) The molecular geometry of the BrO3– ion is __________.
A) trigonal pyramidal
B) trigonal planar
C) bent
D) tetrahedral
E) T-shaped
9) The molecular geometry of the left-most carbon atom in the molecule below is __________.
A) trigonal planar
B) trigonal bipyramidal
C) tetrahedral
D) octahedral
E) T-shaped
10) The molecular geometry of the right-most carbon in the molecule below is __________.
A) trigonal planar
B) trigonal bipyramidal
C) tetrahedral
D) octahedral
E) T-shaped
11) The bond angles marked a, b, and c in the molecule below are about __________, __________, 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°
12) The bond angles marked a, b, and c in the molecule below are about __________, __________, and
__________, respectively.
A) 109.5°, 109.5°, 109.5°
B) 120°, 109.5°, 120°
C) 109.5°, 109.5°, 120°
D) 90°, 180°, 90°
E) 109.5°, 109.5°, 90°
13) The bond angle marked a in the following molecule is about __________.
A) 90°
B) 109.5°
C) 120°
D) 180°
E) 60°
14) The central iodine atom in the ICl4– ion has __________ nonbonded electron pairs and __________
bonded electron pairs in its valence shell.
A) 2, 2
B) 3, 4
C) 1, 3
D) 3, 2
E) 2, 4
15) The central iodine atom in IF5 has __________ unbonded electron pairs and __________ bonded
electron pairs in its valence shell.
A) 1, 5
B) 0, 5
C) 5, 1
D) 4, 1
E) 1, 4
16) The central Xe atom in the XeF4 molecule has __________ unbonded electron pairs and
__________ bonded electron pairs in its valence shell.
A) 1, 4
B) 2, 4
C) 4, 0
D) 4, 1
E) 4, 2
17) An electron domain consists of __________.
a) a nonbonding pair of electrons
b) a single bond
c) a multiple bond
A) a only
B) b only
C) c only
D) a, b, and c
E) b and c
18) The molecular geometry consists of __________.
a) a nonbonding pair of electrons
b) a single bond
c) a multiple bond
A) a only
B) b only
C) c only
D) a, b, and c
E) b and c
19) The electron-domain geometry and the molecular geometry of a molecule of the general formula
ABn are __________.
A) never the same
B) always the same
C) sometimes the same
D) not related
E) mirror images of one another
20) The electron-domain geometry and the molecular geometry of a molecule of the general formula
ABn will always be the same if __________.
A) there are no lone pairs on the central atom
B) there is more than one central atom
C) n is greater than four
D) n is less than four
E) the octet rule is obeyed
21) A molecule has the formula AB3 and the central atom is in a different plane from the surrounding
three atoms. Its molecular shape is __________.
A) tetrahedral
B) trigonal pyramidal
C) linear
D) T-shaped
E) bent
22) PCl5 has __________ electron domains and a __________ molecular arrangement.
A) 6, trigonal bipyramidal
B) 6, tetrahedral
C) 5, square pyramidal
D) 5, trigonal bipyramidal
E) 6, seesaw
23) For molecules of the general formula ABn, n can be greater than four __________.
A) for any element A
B) only when A is an element from the third period or below the third period
C) only when A is boron or beryllium
D) only when A is carbon
E) only when A is Xe
Consider the following species when answering the following questions:
(i) PCl3 (ii) CCl4 (iii) TeCl4 (iv) XeF4 (v) SF6
24) For which of the molecules is the molecular geometry (shape) the same as the VSEPR electron
domain arrangement (electron domain geometry)?
A) (i) and (ii)
B) (i) and (iii)
C) (ii) and (v)
D) (iv) and (v)
E) (v) only
25) Of the molecules below, only __________ is polar.
A) SbF5
B) AsH3
C) I2
D) SF6
E) CH4
26) Of the molecules below, only __________ is nonpolar.
A) CO2
B) H2O
C) NH3
D) HCl
E) TeCl2
27) Of the molecules below, only __________ is polar.
A) CCl4
B) CH4
C) SeF4
D) SiCl4
28) Of the molecules below, only __________ is nonpolar.
A) BF3
B) NF3
C) IF3
D) PBr3
E) BrCl3
29) Three monosulfur fluorides are observed: SF2, SF4, and SF6. Of these, __________ is/are polar.
A) SF2 only
B) SF2 and SF4 only
C) SF4 only
D) SF6 only
E) SF2, SF4, and SF6
30) The molecular geometry of the BeCl2 molecule is __________, and this molecule is __________.
A) linear, nonpolar
B) linear, polar
C) bent, nonpolar
D) bent, polar
E) trigonal planar, polar
31) The molecular geometry of the PF3 molecule is __________, and this molecule is __________.
A) trigonal planar, polar
B) trigonal planar, nonpolar
C) trigonal pyramidal, polar
D) trigonal pyramidal, nonpolar
E) tetrahedral, unipolar
32) Of the following molecules, only __________ is polar.
A) BeCl2
B) BF3
C) CBr4
D) SiH2Cl2
E) Cl2
33) Of the following molecules, only __________ is polar.
A) CCl4
B) BCl3
C) NCl3
D) BeCl2
E) Cl2
34) For molecules with only one central atom, how many lone pairs on the central atom guarantees
molecular polarity?
A) 1
B) 2
C) 1 or 2
D) 3
E) 1 or 3
35) The molecular geometry of the CHF3 molecule is __________, and the molecule is __________.
A) trigonal pyramidal, polar
B) tetrahedral, nonpolar
C) seesaw, nonpolar
D) tetrahedral, polar
E) seesaw, polar
36) The molecular geometry of the BCl3 molecule is __________, and this molecule is __________.
A) trigonal pyramidal, polar
B) trigonal pyramidal, nonpolar
C) trigonal planar, polar
D) trigonal planar, nonpolar
E) trigonal bipyramidal, polar
37) The molecular geometry of the SF6 molecule is __________, and this molecule is __________.
A) trigonal pyramidal, polar
B) octahedral, nonpolar
C) trigonal planar, polar
D) trigonal planar, nonpolar
E) trigonal bipyramidal, polar
38) According to valence bond theory, which orbitals overlap in the formation of the bond in HBr?
A) 1s on H and 4p on Br
B) 1s on H and 4s on Br
C) 1s on H and 3p on Br
D) 2s on H and 4p on Br
E) 2s on H and 3p on Br
Consider the following species when answering the following questions:
(i) PCl3 (ii) CCl4 (iii) TeCl4 (iv) XeF4 (v) SF6
39) Which of the molecules has a see-saw shape?
A) (i)
B) (ii)
C) (iii)
D) (iv)
E) (v)
40) In which of the molecules does the central atom utilize d orbitals to form hybrid orbitals?
A) (i) and (ii)
B) (iii) only
C) (i) and (v)
D) (iii), (iv), and (v)
E) (v) only
41) The combination of two atomic orbitals results in the formation of __________ molecular orbitals.
A) 1
B) 2
C) 3
D) 4
E) 0
42) The electron-domain geometry of a carbon-centered compound is tetrahedral. The hybridization of
the central carbon atom is __________.
A) sp
B) sp2
C) sp3
D) sp3d
E) sp3d2
43) Of the following, only __________ has sp2 hybridization of the central atom.
A) PH3
B) CO32-
C) ICl3
D) l3–
E) PF5
44) Of the following, the central atom is sp3d2 hybridized only in __________.
A) PCl5
B) XeF4
C) PH3
D) Br3–
E) BeF2
45) The sp3d2 atomic hybrid orbital set accommodates __________ electron domains.
A) 2
B) 3
C) 4
D) 5
E) 6
46) The sp2 atomic hybrid orbital set accommodates __________ electron domains.
A) 2
B) 3
C) 4
D) 5
E) 6
47) The hybridizations of nitrogen in NF3 and NH3 are __________ and __________, respectively.
A) sp2, sp2
B) sp, sp3
C) sp3, sp
D) sp3, sp3
E) sp2, sp3
48) The hybridizations of iodine in IF3 and IF5 are __________ and __________, respectively.
A) sp3, sp3d
B) sp3d, sp3d2
C) sp3d, sp3
D) sp3d2, sp3d
E) sp3d2, sp3d2
49) The hybridizations of bromine in BrF5 and of arsenic in AsF5 are __________ and __________,
respectively.
A) sp3, sp3d
B) sp3d, sp3d2
C) sp3d, sp3
D) sp3d2, sp3d
E) sp3d2, sp3d2
50) The hybrid orbitals used for bonding by the sulfur atom in the SF4 molecule are __________
orbitals.
A) sp
B) sp2
C) sp3
D) sp3d
E) sp3d2
51) The hybrid orbitals used for bonding by Xe in the unstable XeF2 molecule are __________ orbitals.
A) sp2
B) sp3
C) sp3d
D) sp3d2
E) sp
52) The hybridization scheme for BeF2 is __________.
A) sp
B) sp2
C) sp3
D) sp3d
E) sp3d2
53) The hybridization of the oxygen atom labeled y in the structure below is __________. The C-O-H
bond angle is __________.
A) sp, 180°
B) sp2, 109.5°
C) sp3, 109.5°
D) sp3d2, 90°
E) sp, 90°
54) The electron-domain geometry of the AsF5 molecule is trigonal bipyramidal. The hybrid orbitals
used by the As atom for bonding are __________ orbitals.
A) sp2d2
B) sp3
C) sp3d2
D) sp3d
E) sp2
55) __________ hybrid orbitals are used for bonding by Xe in the XeF4 molecule.
A) sp2
B) sp3
C) sp3d
D) sp3d2
E) sp
56) In which of the molecules is the central atom sp3d2 hybridized?
A) (i) and (ii)
B) (iii) only
C) (iii) and (iv)
D) (iv) and (v)
E) (v) only
57) There are __________ unhybridized p atomic orbitals in an sp-hybridized carbon atom.
A) 0
B) 1
C) 2
D) 3
E) 4
58) There are __________ unhybridized p atomic orbitals in an sp2-hybridized carbon atom.
A) 0
B) 1
C) 2
D) 3
E) 4
59) When three atomic orbitals are mixed to form hybrid orbitals, how many hybrid orbitals are formed?
A) one
B) six
C) three
D) four
E) five
60) When four atomic orbitals are mixed to form hybrid orbitals, how many hybrid orbitals are formed?
A) one
B) six
C) three
D) four
E) five
61) The blending of one s atomic orbital and two p atomic orbitals produces __________.
A) three sp hybrid orbitals
B) two sp2 hybrid orbitals
C) three sp3 hybrid orbitals
D) two sp3 hybrid orbitals
E) three sp2 hybrid orbitals
62) A triatomic molecule cannot be linear if the hybridization of the central atoms is __________.
A) sp
B) sp2
C) sp3
D) sp2 or sp3
E) sp2d or sp3d2
63) Valence bond theory does not address the issue of __________.
A) excited states of molecules
B) molecular shape
C) covalent bonding
D) hybridization
E) multiple bonds
64) A typical double bond __________.
A) is stronger and shorter than a single bond
B) consists of one σ bond and one π bond
C) imparts rigidity to a molecule
D) consists of two shared electron pairs
E) All of the above answers are correct.
65) A typical triple bond __________.
A) consists of one σ bond and two π bonds
B) consists of three shared electrons
C) consists of two σ bonds and one π bond
D) consists of six shared electron pairs
E) is longer than a single bond
66) In a polyatomic molecule, “localized” bonding electrons are associated with __________.
A) one particular atom
B) two particular atoms
C) all of the atoms in the molecule
D) all of the π bonds in the molecule
E) two or more σ bonds in the molecule
67) There are __________ σ bonds and __________ π bonds in H3C–CH2–CH CH–CH2–C CH.
A) 14, 2
B) 10, 3
C) 12, 2
D) 13, 2
E) 16, 3
68) Which of the following molecules or ions will exhibit delocalized bonding?
SO2 SO3 SO32-
A) SO2, SO3, and SO32-
B) SO32- only
C) SO2 and SO3
D) SO3 and SO32-
E) None of the above will exhibit delocalized bonding.
69) Which of the following molecules or ions will exhibit delocalized bonding?
NO2– NH4+ N3–
A) NH4+ and N3–
B) NO2– only
C) NO2–, NH4+, and N3–
D) N3– only
E) NO2– and N3–
70) 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) trigonal planar electron domain geometry
71) In a typical multiple bond, the σ bond results from overlap of __________ orbitals and the π bond(s)
result from overlap of __________ orbitals.
A) hybrid, atomic
B) hybrid, hybrid
C) atomic, hybrid
D) hybrid, hybrid or atomic
E) hybrid or atomic, hybrid or atomic
72) The carbon-carbon σ bond in ethylene, H2CCH2, results from the overlap of __________.
A) sp hybrid orbitals
B) sp3 hybrid orbitals
C) sp2 hybrid orbitals
D) s atomic orbitals
E) p atomic orbitals
73) The π bond in ethylene, H2CCH2, results from the overlap of __________.
A) sp3 hybrid orbitals
B) s atomic orbitals
C) sp hybrid orbitals
D) sp2 hybrid orbitals
E) p atomic orbitals
74) A typical triple bond consists of __________.
A) three sigma bonds
B) three pi bonds
C) one sigma and two pi bonds
D) two sigma and one pi bond
E) three ionic bonds
75) A typical double bond consists of __________.
A) three sigma bonds
B) three pi bonds
C) one sigma and two pi bonds
D) one sigma and one pi bond
E) three ionic bonds
76) The N-N bond in HNNH consists of __________.
A) one σ bond and one π bond
B) one σ bond and two π bonds
C) two σ bonds and one π bond
D) two σ bonds and two π bonds
E) one σ bond and no π bonds
77) The hybridization of the terminal carbons in the H2CC CH2 molecule is __________.
A) sp
B) sp2
C) sp3
D) sp3d
E) sp3d2
78) The hybridization of nitrogen in the H C N: molecule is __________.
A) sp
B) s2p
C) s3p
D) sp2
E) sp3
79) The hybridization of carbon in the H C N: molecule is __________.
A) sp2
B) s2p
C) s3p
D) sp
E) sp3
80) The hybridization of the carbon atom labeled x in the molecule below is __________.
A) sp
B) sp2
C) sp3
D) sp3d
E) sp3d2
81) The hybridization of the oxygen atom labeled x in the structure below is __________.
A) sp
B) sp2
C) sp3
D) sp3d
E) sp3d2
82) The Lewis structure of carbon dioxide is given below. The hybridization of the carbon atom in
carbon dioxide is __________.
A) sp3
B) sp2
C) sp
D) sp2d
E) sp2d2
83) Electrons in __________ bonds remain localized between two atoms. Electrons in __________
bonds can become delocalized between more than two atoms.
A) pi, sigma
B) sigma, pi
C) pi, pi
D) sigma, sigma
E) ionic, sigma