Deck 9: Molecular Geometry and Bonding Theories

Question 1

Which of the following molecules is T-shaped?

A) NCl₃
B) PCl₃
C) SCl₃
D) ICl₃
E) COCl₂

Answer 1

ICl₃

Question 2

In VSEPR theory, molecular geometry is determined by __________

A) electron-proton attractive forces.
B) electron-electron attractive forces.
C) electron-electron repulsive forces.
D) proton-proton repulsive forces.
E) electron-nucleus attractive forces.

Answer 2

electron-electron repulsive forces.

Question 3

Which of the following compounds has a trigonal bipyramidal shape?

A) ICl₃
B) BrF₅
C) PCl₅
D) PH₃
E) SiF₄

Answer 3

PCl₅

Question 4

What is the geometry of the ClF₄^- ion?

A) square planar
B) square pyramidal
C) trigonal pyramidal
D) tetrahedral
E) seesaw

Question 5

Which of the following has the largest bond angle?

A) CF₄
B) NF₃
C) F₂O
D) NF₂^-
E) NH₃

Question 6

Determine the molecular geometry of CF₂Cl₂.

A) linear
B) bent
C) trigonal bipyramidal
D) tetrahedral
E) trigonal pyramidal

Question 7

Which of the following compounds has the same molecular shape as CCl₃H?

A) SiF₄
B) KrF₄
C) SF₄
D) C₂H₄
E) C₂H₂

Question 8

What is the geometry of the triiodide ion (I₃^-)?

A) linear
B) bent
C) tetrahedral
D) trigonal pyramidal
E) trigonal planar

Question 9

Which electron-pair geometry has the lowest electron-electron repulsive forces?

A) linear
B) trigonal planar
C) tetrahedral
D) trigonal bipyramidal
E) octahedral

Question 10

Which of the following molecules has a trigonal pyramid shape?

A) KrF₄
B) COCl₂
C) SeO₃^2-
D) NH₄⁺
E) O₃

Question 11

Which bond angle is the smallest?

A) H - C - H in CH₄
B) H - C - H in C₂H₄
C) H - C - H in H₂CO
D) H - C - C in C₂H₂
E) H - C - O in H₂CO

Question 12

Which of the following molecules is linear?

A) H₂O
B) H₂S
C) ICl₃
D) I₃^-
E) SO₂

Question 13

For the series methane, ammonia, and water, the bond angle increases in the following order: H₂O < NH₃ < CH₄. This trend is due to __________

A) a decreasing effective nuclear charge.
B) a decrease in the number of lone pairs.
C) an increase in atomic radius.
D) an increase in the polarity of the molecules.
E) an increasing effective nuclear charge.

Question 14

Which of the following compounds has a square pyramid shape?

A) ICl₃
B) BrF₅
C) PCl₅
D) PH₃
E) SiF₄

Question 15

Which of the following ions is linear?

A) SCN^-
B) NO₂^-
C) SO₃^2-
D) NH₄⁺
E) SO₂^2-

Question 16

Arrange the interactions between pairs of electrons in order of increasing strength.

A) bonding pair-bonding pair < lone pair-bonding pair < lone pair-lone pair
B) bonding pair-bonding pair < lone pair-lone pair < lone pair-bonding pair
C) lone pair-lone pair < lone pair-bonding pair < bonding pair-bonding pair
D) lone pair-lone pair < bonding pair-bonding pair < lone pair-bonding pair
E) lone pair-bonding pair < bonding pair-bonding pair < lone pair-lone pair

Question 17

The correct H - N - H bond angle in NH₃ is __________

A) the same as the H - O - H angle in water.
B) exactly 109.5.
C) greater than 109.5.
D) less than 109.5°.
E) 120°.

Question 18

What is the molecular geometry of SF₄?

A) tetrahedral
B) square pyramidal
C) seesaw
D) square planar
E) T-shaped

Question 19

Which of the following compounds has the same shape as SO₂?

A) H₂O
B) HCN
C) ICl₃
D) OCS
E) CO₂

Question 20

Which of the following is a planar molecule?

A) NH₃
B) PCl₅
C) KrF₄
D) CH₃COOH
E) SiH₄

Question 21

Benzene (C₆H₆) is a cyclic, nonpolar molecule. By removing one of the hydrogens and replacing it with another atom or group, this substituted benzene becomes polar. Which of the following substituted benzenes is the most polar?

A) C₆H₅F (fluorobenzene)
B) C₆H₅Br (bromobenzene)
C) C₆H₅Cl (chlorobenzene)
D) C₆H₅I (iodobenzene)
E) C₆H₅CH₃ (methylbenzene)

Question 22

Which of the following molecules has a carbon atom that is sp³ hybridized?

A) C₂H₂
B) H₂CO
C) CH₃Cl
D) C₂H₄
E) C₂H₂Cl₂

Question 23

All homonuclear diatomic molecules __________

A) have polar bonds.
B) are polar.
C) are nonpolar.
D) cannot vibrate.
E) are liquids.

Question 24

Which of the following has a central atom with the same hybridization as the oxygen in water?

A) SO₂
B) OCS
C) CS₂
D) NH₃
E) CO₂

Question 25

Which of the following diagrams shows the correct orientation of the dipole in sulfur dioxide?

A)
B)
C)
D)

Question 26

What is the hybridization of the bromine atom in BrF₅?

A) sp³
B) sp³d
C) sp³d²
D) sp
E) sp²

Question 27

Which of the following molecules has a central atom that is sp³ hybridized?

A) C₂H₂
B) H₂CO
C) H₂S
D) C₂H₄
E) C₂H₂Cl₂

Question 28

What is the hybridization of the oxygen in the H₃O⁺ ion?

A) sp²
B) sp³
C) sp³d
D) sp
E) sp³d²

Question 29

Identify the polar molecule.

A) CF₄
B) SiH₄
C) CHCl₃
D) CS₂
E) CO₂

Question 30

Which of the following has a central atom with the same hybridization as the carbon in formaldehyde (H₂CO)?

A) SO₂
B) OCS
C) ICl₃
D) I₃^-
E) C₂H₂

Question 31

What is the hybridization of the central iodine atom in I₃^-?

A) sp
B) sp²
C) sp³d
D) sp³d²
E) sp³

Question 32

What type of hybridization is needed to describe the bonding in a T-shaped molecule?

A) sp²
B) sp³
C) sp³d
D) sp
E) sp³d²

Question 33

Which of the following shows the orientation of the net dipole for OCS?

A)
B)
C)
D)

Question 34

What is the molecular geometry of SF₄O?

A) pentagonal
B) tetrahedral
C) trigonal bipyramidal
D) trigonal planar
E) square pyramidal

Question 35

Which of the following compounds is the most polar?

A) NH₃
B) PH₃
C) AsH₃
D) SbH₃
E) BiH₃

Question 36

What type of hybridization is needed to describe the bonding in a seesaw-shaped molecule?

A) sp²
B) sp³
C) sp³d
D) sp
E) sp³d²

Question 37

Which of the following compounds has the smallest dipole moment?

A) CF₂Cl₂
B) CF₃Cl
C) CF₄
D) CFCl₃
E) CHFCl₂

Question 38

Which of the following molecules or ions is not polar?

A) O₃
B) H₂O
C) SO₂
D) I₃^-
E) S₃

Question 39

What hybridization is needed to describe the square planar molecular geometry of KrF₄?

A) sp³
B) sp³d
C) sp³d²
D) sp²
E) sp

Question 40

Which of the following compounds has the largest dipole moment?

A) CH₂Cl₂
B) CH₃Cl
C) CHCl₃
D) CCl₄
E) CH₄

Question 41

Which statement regarding a pi bond between two carbon atoms is correct?

A) The region of high electron density lies along the bond axis connecting the nuclei of the two atoms.
B) Can be described by the overlap of sp hybrid orbitals from each atom.
C) Can be described by the overlap of sp² hybrid orbitals from each atom.
D) Can be described by the overlap of p atomic orbitals from each atom.
E) Can be described by the overlap of a p atomic orbital from one atom with an sp² hybrid orbital from the other atom.

Question 42

Which statement regarding a sigma bond between two carbon atoms is not correct?

A) The region of electron density lies along the bond axis connecting the nuclei of the two atoms.
B) The bond can be described by the overlap of sp hybrid orbitals from each atom.
C) The bond can be described by the overlap of sp² hybrid orbitals from each atom.
D) The bond can be described by the overlap of sp³d hybrid orbitals from each atom.
E) The bond can be described by the overlap of an sp² hybrid orbital from one atom with an sp³ hybrid orbital from the other atom.

Question 43

Both cyclohexane (C₆H₁₂) and benzene (C₆H₆) have the carbon atoms forming a six-member ring. In a valence bond picture of the C - C bonds, _____ hybrid orbitals would overlap for cyclohexane, and _____ hybrid orbitals would overlap for benzene.

A) sp; sp
B) sp; sp²
C) sp²; sp³
D) sp³; sp²
E) sp³; sp

Question 44

For the molecule CH₃CHCHCH₃, the local molecular geometry around the second carbon atom from the end and its hybridization are ___________

A) trigonal bipyramid and sp.
B) trigonal planar and sp³.
C) trigonal planar and sp².
D) tetrahedral and sp³.
E) linear and sp.

Question 45

What is the valence electron molecular orbital electron configuration of C₂?

A)
B)
C)
D)
E)

Question 46

Which type of molecular orbital is used to describe electron density building up above and below the internuclear axis to form a bond?

A) ""
B) ""
C) "*"
D) "*"
E) s

Question 47

Which type of molecular orbital contains a node perpendicular to the axis connecting two atomic nuclei?

A) ""
B) ""
C) "*"
D) s
E) p

Question 48

Which type of molecular orbital has maximum electron density above and below the internuclear axis but zero density in a plane perpendicular to the internuclear axis?

A) ""
B) ""
C) "*"
D) "*"
E) p

Question 49

Which type of molecular orbital has only one nodal plane, which contains the atomic nuclei?

A) ""
B) ""
C) "*"
D) "*"
E) s

Question 50

Which statement regarding a pi bond between two carbon atoms is correct?

A) Regions of high electron density lie above and below the bond axis connecting the nuclei of the two atoms.
B) Can be described by the overlap of sp hybrid orbitals from each atom.
C) Can be described by the overlap of sp² hybrid orbitals from each atom.
D) Can be described by the overlap of sp³ atomic orbitals from each atom.
E) Can be described by the overlap of a p atomic orbital from one atom with an sp² hybrid orbital from the other atom.

Question 51

Ethanol has the formula CH₃CH₂OH. The central carbon atom has a _____ local molecular geometry and _____ hybridization.

A) trigonal planar; sp
B) tetrahedral; sp³
C) tetrahedral; sp²
D) seesaw; sp²
E) seesaw, sp³

Question 52

Ethanol has the formula CH₃CH₂OH. The end carbon atom has a _____ local molecular geometry and _____ hybridization.

A) trigonal planar; sp
B) tetrahedral; sp³
C) tetrahedral; sp²
D) seesaw; sp²
E) seesaw; sp³

Question 53

Which of the following compounds has a central atom with the same hybridization as PCl₅?

A) IF₆⁺
B) SiF₄
C) BrF₅
D) SbF₅
E) XeF₄

Question 54

What are the hybridizations of the carbon atoms in CH₃CH₂COH, in order from left to right?

A) sp³, sp³, sp²
B) sp³, sp³, sp³
C) sp³, sp², sp³
D) sp², sp², sp³
E) sp³, sp², sp²

Question 55

Ethanol has the formula CH₃CH₂OH. The oxygen atom has a _____ local molecular geometry and _____ hybridization.

A) trigonal planar; sp
B) tetrahedral; sp³
C) tetrahedral; sp²
D) seesaw; sp²
E) bent; sp³

Question 56

Which type of molecular orbital is used to describe a buildup of electron density along the axis connecting two atomic nuclei to form a bond?

A) ""
B) ""
C) "*"
D) "*"
E) p_y

Question 57

What is the hybridization of the iodine atom in ICl₃?

A) sp²
B) sp³d²
C) sp³d
D) sp³
E) sp

Question 58

Which of the following has a local molecular geometry about a carbon atom that is trigonal planar?

A) CH₃CH₂OH
B) CH₃OH
C) C₂H₄
D) CH₃OCH₃
E) C₂H₂

Question 59

For the molecule CH₃CHCHCH₃, the local molecular geometry around a carbon atom at the end and its hybridization are ___________

A) trigonal bipyramid and sp.
B) trigonal planar and sp³.
C) trigonal planar and sp².
D) tetrahedral and sp³.
E) linear and sp.

Question 60

The local molecular geometry and the hybridization around each carbon atom in benzene (C₆H₆ with a hexagonal ring structure) is _______

A) square planar and sp.
B) trigonal planar and sp.
C) tetrahedral and sp³.
D) trigonal planar and sp².
E) T-shaped and sp².

Question 61

Using the energy level diagram below, determine the bond order of the PO molecule?

A) 2
B) 2.5
C) 1.5
D) 1
E) 0.5

Question 62

Which one of the following statements regarding molecular orbitals for diatomic molecules is not correct?

A) An atomic orbital on one atom combines with an atomic orbital on the other atom to form two molecular orbitals.
B) 2p atomic orbitals only form  and * molecular orbitals.
C) 2s atomic orbitals only form  and * atomic orbitals.
D) "" orbitals are symmetric with respect to rotation around the internuclear axis;  orbitals do not have this symmetry.
E) A bonding molecular orbital describes the build-up of negatively charged electrons between the nuclei.

Question 63

Which statement concerning benzene is not correct?

A) A second Lewis structure is needed to describe benzene.
B) All the  bonds originate from p atomic orbitals.
C) Benzene does not have a dipole moment.
D) The carbon atomic orbitals are sp² hybridized.
E) Benzene has both long and short carbon-carbon bonds.

Question 64

Use energy levels of diatomic molecules derived from molecular orbital theory to predict the magnetic properties of the oxygen molecule O₂ and the peroxide anion O₂^2-.

A) oxygen (paramagnetic); peroxide (paramagnetic)
B) oxygen (paramagnetic); peroxide (diamagnetic)
C) oxygen (diamagnetic); peroxide (paramagnetic)
D) oxygen (diamagnetic); peroxide (diamagnetic)
E) Neither have magnetic properties, only metals have magnetic properties.

Question 65

Use MO theory to predict the bond orders of the following molecular ions. Which one do you predict does not exist?

A) N₂⁺
B) O₂⁺
C) C₂⁺
D) F₂^2-
E) O₂^2-

Question 66

Boron nitride is being investigated in frontier research directed at producing novel electronic devices. If you used the following energy level diagram for the molecular orbitals of boron nitride, BN, what would you predict?
(I) Boron nitride is diamagnetic.
(II) Boron nitride has a bond order of 2.
(III) Boron nitride is paramagnetic.
(IV) The bond in BN^- is stronger than the bond in BN.

A) I and II
B) II and III
C) I, II, and IV
D) III
E) IV

Question 67

Boron nitride, BN, is a new high tech material. According to the molecular orbital energy level diagram below, which one of the following statements is not correct about boron nitride?

A) The bond order in BN is 2.0.
B) The cation BN⁺ has a longer bond than BN.
C) BN is paramagnetic.
D) The bond order in the cation BN⁺ is 1.5.
E) The anion BN^- has a weaker bond than BN.

Question 68

According to the molecular orbital energy level diagram below, which one of the following statements is not correct about NO, NO⁺, and ?

A) The bond order in NO is 2.5.
B) NO⁺ has the shortest bond.
C) Only one of these species is paramagnetic.
D) The bond order in is 2.0.
E) has the weakest bond.

Question 69

Use energy levels of diatomic molecules derived from molecular orbital theory to predict the bond order of the oxygen molecule O₂ and the peroxide anion O₂^2-.

A) oxygen (bond order = 2); peroxide (bond order = 3)
B) oxygen (bond order = 2); peroxide (bond order = 2)
C) oxygen (bond order = 4); peroxide (bond order = 4)
D) oxygen (bond order = 4); peroxide (bond order = 5)
E) oxygen (bond order = 2); peroxide (bond order = 1)

Question 70

What is the bond order of B₂?

A) 0
B) 1
C) 2
D) 3
E) 1.5

Question 71

Predict the bond order of the NO⁺ molecular ion.

A) 2
B) 2.5
C) 3
D) 1
E) 1.5

Question 72

Which of these molecules have a dipole moment?

A) PCl₅ and SiCl₄
B) POCl₃, SO₂Cl₂, and SO₃
C) POCl₃ and SO₂Cl₂
D) PCl₅, POCl₃, SOCl₂, SO₃, and SiCl₄
E) PCl₅, SF₆, SO₃, and SiCl₄

Question 73

Which of the following molecules has a bond order that is less than one?

A) F₂
B) He₂^-
C) Ne₂²⁺
D) N₂
E) O₂^2-

Question 74

Which one of the following molecules has a bond order of 3?

A) Li₂
B) Be₂
C) N₂
D) F₂
E) C₂

Question 75

Which of the following statements about bonds between two carbon atoms is/are correct? (I) Bond strength increases as more electrons are shared between the atoms.
(II) Bond strength increases as the overlap between atomic orbitals increases.
(III) Hybrid orbitals are used to describe (account for) the geometry (bond angles) around each carbon atom.

A) I
B) II
C) III
D) Only two of these are correct statements.
E) All three are correct statements.

Question 76

Which of the following molecules is paramagnetic?

A) Li₂
B) C₂
C) B₂
D) N₂
E) F₂

Question 77

Which one of the following molecules is paramagnetic? These molecules are described by the MO energy diagram below.

A) Li₂
B) C₂^2-
C) N₂^2-
D) N₂²⁺
E) C₂

Question 78

Oxygen has two common molecular anions: peroxide (O₂^2-) and superoxide (O₂^-). Use the MO energy level diagram below to identify which one of the following statements is not correct.

A) The bond order of the peroxide is 1.
B) The superoxide has a shorter bond than the peroxide.
C) Like O₂, the peroxide is paramagnetic.
D) The superoxide has a stronger bond than the peroxide.
E) Oxygen, O₂, has a stronger bond than either of these oxides.

Question 79

Predict the bond order of the NO^- molecular ion.

A) 2
B) 2.5
C) 3
D) 1
E) 1.5

Question 80

Which of the following molecules is paramagnetic?

A) F₂
B) O₂
C) C₂
D) Be₂
E) "C₂"