Chapter 9
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
Answer: D
According to VSEPR theory, if there are three electron domains in the
valence shell of an atom, they
will be arranged in a(n)
__________ geometry.
A) octahedral
B) linear
C)
tetrahedral
D) trigonal planar
E) trigonal bipyramidal
Answer: D
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
Answer: C
The electron-domain geometry of __________ is tetrahedral.
A)
CBr4
B) PH3
C) CCl2BR2
D) XeF4
E) all of the above
except XeF4
Answer: E
The O–C–O bond angle in the CO32- ion is approximately
__________.
A) 90°
B) 109.5°
C) 120°
D)
180°
E) 60°
Answer: C
The Cl–C–Cl bond angle in the CCl O2 molecule (C is the central atom)
is slightly __________.
A) greater than 90°
B) less than
109.5°
C) less than 120°
D) greater than 120°
E)
greater than 109.5°
Answer: C
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°.
Answer: D
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
Answer: D
According to VSEPR theory, if there are three electron domains on a
central atom, they will be
arranged such that the angles between
the domains are __________.
A) 90°
B) 180°
C)
109.5°
D) 360°
E) 120°
Answer: E
According to VSEPR theory, if there are two electron domains on a
central atom, they will be arranged
such that the angles between
the domains are __________.
A) 360°
B) 120°
C)
109.5°
D) 180°
E) 90°
Answer: D
According to VSEPR theory, if there are four electron domains on a
central atom, they will be
arranged such that the angles between
the domains are __________.
A) 120°
B) 109.5°
C)
180°
D) 360°
E) 90°
Answer: B
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
Answer: C
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
Answer: A
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
Answer: B
Consider the following species when answering the following
questions:
(i) PCl3 (ii) CCl4 (iii) TeCl4 (iv) XeF4 (v) SF6
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
Answer: C
Of the molecules below, only __________ is polar.
A)
SbF5
B) AsH3
C) 2I
D) SF6
E) CH4
Answer: B
The combination of two atomic orbitals results in the formation of
__________ molecular orbitals.
A) 1
B) 2
C) 3
D)
4
E) 0
Answer: B
The 3 2 sp d atomic hybrid orbital set accommodates __________
electron domains.
A) 2
B) 3
C) 4
D) 5
E) 6
Answer: E
The 2 sp atomic hybrid orbital set accommodates __________ electron
domains.
A) 2
B) 3
C) 4
D) 5
E) 6
Answer: B
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
Answer: C
The blending of one s atomic orbital and two p atomic orbitals
produces __________.
A) three sp hybrid orbitals
B) two 2 sp
hybrid orbitals
C) three 3 sp hybrid orbitals
D) two 3 sp
hybrid orbitals
E) three 2 sp hybrid orbitals
Answer: E
A triatomic molecule cannot be linear if the hybridization of the
central atoms is __________.
A) sp
B) 2 sp
C) 3
sp
D) 2 sp or 3 sp
E) 2 sp d or 3 2 sp d
Answer: D
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.
Answer: E
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
Answer: A
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
Answer: B
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
Answer: B
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
Answer: A
The carbon-carbon σ bond in ethylene, CH CH 2 2 , results from the
overlap of __________.
A) sp hybrid orbitals
B) 3 sp hybrid
orbitals
C) 2 sp hybrid orbitals
D) s atomic
orbitals
E) p atomic orbitals
Answer: C
The π bond in ethylene, CH CH 2 2 , results from the overlap of
__________.
A) 3 sp hybrid orbitals
B) s atomic
orbitals
C) sp hybrid orbitals
D) 2 sp hybrid
orbitals
E) p atomic orbitals
Answer: E
In order for rotation to occur about a double bond,
__________.
A) the σ bond must be broken
B) the π bond must
be broken
C) the bonding must be delocalized
D) the bonding
must be localized
E) the σ and π bonds must both be broken
Answer: B
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
Answer: C
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
Answer: A
The hybridization of the terminal carbons in the H C=C=CH 2 2
molecule is __________.
A) sp
B) 2 sp
C) 3 sp
D) 3
sp d
E) 3 2 sp d
Answer: B
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
Answer: B
The bond order of any molecule containing equal numbers of bonding
and antibonding electrons is
__________.
A) 0
B)
1
C) 2
D) 3
E) 1/2
Answer: A
An antibonding π orbital contains a maximum of __________
electrons.
A) 1
B) 2
C) 4
D) 6
E) 8
Answer: B
According to MO theory, overlap of two s atomic orbitals produces
__________.
A) one bonding molecular orbital and one hybrid
orbital
B) two bonding molecular orbitals
C) two bonding
molecular orbitals and two antibonding molecular orbitals
D) two
bonding molecular orbitals and one antibonding molecular
orbital
E) one bonding molecular orbital and one antibonding
molecular orbital
Answer: E
Molecular Orbital theory correctly predicts paramagnetism of oxygen
gas, O2 . This is because
__________.
A) the bond order in
O2 can be shown to be equal to 2.
B) there are more electrons in
the bonding orbitals than in the antibonding orbitals.
C) the
energy of the 2p π MOs is higher than that of the σ2pMO
D) there
are two unpaired electrons in the MO electron configuration of
O2
E) the O–O bond distance is relatively short
Answer: D
Molecular Orbital theory correctly predicts diamagnetism of fluorine
gas, F2 . This is because
__________.
A) the bond order in
F2 can be shown to be equal to 1.
B) there are more electrons in
the bonding orbitals than in the antibonding orbitals.
C) all
electrons in the MO electron configuration of F2 are paired.
D)
the energy of the 2p π MOs is higher than that of the σ2pMO
E)
the F–F bond enthalpy is very low
Answer: C