Deck 10: Bonding and Molecular Structure: Orbital Hybridization and Molecular Orbitals

Question 1

For which of the following molecules or ions does the central atom have sp hybridization: N₃^-,O₃,and SF₃⁺?

A) N₃^- only
B) O₃ only
C) SF₃⁺ only
D) O₃ and SF₃⁺
E) SF₃⁺and N₃^-

Answer 1

N₃^- only

Question 2

How many sigma ( $\sigma$ )bonds and pi ( $\pi$ )bonds are in the following molecule?

A) seven $\sigma$ and three $\pi$
B) seven $\sigma$ and two $\pi$
C) five $\sigma$ and five $\pi$
D) five $\sigma$ and three $\pi$
E) five $\sigma$ and two $\pi$

Answer 2

seven $\sigma$ and three $\pi$

Question 3

The hybridization of the nitrogen atom in NH₄⁺ is _____.

A) sp
B) sp²
C) sp³
D) sp⁴
E) sp⁶

Answer 3

sp³

Question 4

To form a molecule with a linear electron pair geometry,what set of pure atomic orbitals must be mixed?

A) one s and one p
B) one s and two p
C) one s and three p
D) two s and one p
E) zero s and three p

Question 5

What is the hybridization of the central nitrogen atom in N₂O?

A) sp
B) sp²
C) sp³
D) none

Question 6

What is the maximum number of hybridized orbitals that can be formed by a fluorine atom?

A) 1
B) 2
C) 3
D) 4
E) 6

Question 7

Which of the following does $\underline{\text{ not }}$ contain at least one pi bond?

A) HCN
B) C₂H₆
C) CO
D) C₂H₂
E) All of them have one or more pi bonds.

Question 8

Which of the following statements concerning valence bond (VB)theory is/are CORRECT?
1)VB theory can describe molecular bonding in excited states.
2)VB theory assumes that electrons are localized between pairs of atoms.
3)VB theory predicts localized lone pairs of electrons.

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1,2,and 3

Question 9

How many sigma ( $\sigma$ )bonds and pi ( $\pi$ )bonds are in carbon monoxide?

A) three $\sigma$ ,zero $\pi$
B) two $\sigma$ ,one $\pi$
C) two $\sigma$ ,two $\pi$
D) one $\sigma$ ,two $\pi$
E) one $\sigma$ ,one $\pi$

Question 10

How many sigma and pi bonds are in the molecule pictured below?

A) thirteen sigma bonds and one pi bond
B) eleven sigma bonds and two pi bonds
C) thirteen sigma bonds and two pi bonds
D) eleven sigma bonds and five pi bonds
E) five sigma bonds and eleven pi bonds

Question 11

What is the hybridization of each carbon atom in benzene,C₆H₆? Benzene contains a six-member carbon ring.

A) sp
B) sp²
C) sp³
D) sp⁴
E) sp⁵

Question 12

What is the molecular geometry around a central atom that is sp³ hybridized and has one lone pair of electrons?

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

Question 13

What is the hybridization of the central atom in a molecule with a trigonal-planar molecular geometry?

A) sp
B) sp²
C) sp³
D) sp⁴
E) none

Question 14

Which of the following statements is/are CORRECT according to valence bond theory?
1)Elelctron density in a pi bond is greatest along the axis of the bond.
2)The overlap of two adjacent p orbitals can result in a sigma bond or a pi bond,depending on the p-orbital orientations.
3)Bonds are formed in molecules through the overlap of valence electron atomic orbitals.

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1,2,and 3

Question 15

What is the hybridization of the sulfur atom in SO₄^2-?

A) sp
B) sp²
C) sp³
D) none

Question 16

For which of the following molecules and ions does the central atom have sp² hybridization? (The central atom is listed first in each formula below.)

A) SO₄^2-
B) CO₂
C) NOBr
D) SBr₂
E) N₂O

Question 17

What is the hybridization of the sulfur atom in SCl₂?

A) sp
B) sp²
C) sp³
D) none

Question 18

Which of the following statements concerning molecular orbital (MO)bond theory is/are CORRECT?
1)MO theory can describe molecular bonding in excited states.
2)Molecular orbitals are obtained from the combination of atomic orbitals.
3)MO theory predicts that electrons are delocalized over the molecule through molecular orbitals.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Question 19

Which of the following statements concerning hybrid orbitals is/are CORRECT?
1)The number of hybrid orbitals equals the number of atomic orbitals that are used to create the hybrids.
2)When atomic orbitals are hybridized,the s orbital and at least one p orbital are always hybridized.
3)To create tetrahedral structures,the s orbital and all three p orbitals must be hybridized.

A) 1 only
B) 2 only
C) 3 only
D) 2 and 3
E) 1,2,and 3

Question 20

For which of the following molecules does the carbon atom have sp³ hybridization?

A) Cl₂CO
B) CO
C) CS₂
D) CH₂Cl₂
E) HCN

Question 21

All of the following statements concerning molecular orbital (MO)theory are correct EXCEPT

A) the Pauli exclusion principle is obeyed.
B) Hund's rule is obeyed.
C) electrons are assigned to orbitals of successively higher energy.
D) a bonding molecular orbital is lower in energy than its parent atomic orbitals.
E) the combination of two atomic orbitals creates only one molecular orbital.

Question 22

Ammonia reacts with oxygen and water to produce nitric acid.What change in hybridization of the nitrogen atom occurs in this reaction?

A) sp³ to sp²
B) sp³ to sp
C) sp² to sp³
D) sp² to sp
E) no change

Question 23

Which of the following concerning $\sigma$ and $\pi$ bonds is/are correct?
1)Sigma bonds may only be formed from unhybridized orbitals.
2)Pi bonds are formed from unhybridized p orbitals.
3)A pi bond has an electron distribution above and below the bond axis.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 2 and 3

Question 24

Upon combustion,ethene (C₂H₄)is converted to carbon dioxide and water.What change in the hybridization of carbon occurs in this reaction?

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

Question 25

For which of the following compounds is it possible for cis and trans isomers to exist?

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Question 26

Which of the underlined atoms (C₁,C₂,N,and O)are sp hybridized?

A) C₁ and C₂
B) C₁,C₂,N,and O
C) N and O
D) C₁,C₂,and N
E) none

Question 27

What is the hybridization of an atom that has 1 $\sigma$ bond,0 $\pi$ bonds,and 3 lone pairs?

A) sp
B) sp²
C) sp³
D) sp⁴
E) none

Question 28

Dichloromethane,CH₂Cl₂,is a common organic solvent.Which of the following statements concerning dichloromethane is/are CORRECT?
1)CH₂Cl₂ has two isomers.For one isomer of CH₂Cl₂,the chlorine atoms are adjacent to each other and the molecule is polar.
2)CH₂Cl₂ has two isomers.For one isomer of CH₂Cl₂,the chlorine atoms are on opposites sides of the carbon atom and the molecule is nonpolar.
3)The hybridization of the central carbon atom is sp³.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 1,2,and 3

Question 29

What is the hybridization of the nitrogen atom?

A) sp
B) sp²
C) sp³
D) sp⁴
E) none

Question 30

Which of the following characteristics apply to NCl₃?
1)polar bonds
2)nonpolar molecule
3)triangular-planar molecular shape
4)sp² hybridized N atom

A) 1 only
B) 1 and 2
C) 3 and 4
D) 1,2,and 3
E) 1,2,3,and 4

Question 31

Nitric acid,HNO₃,dissociates in water to form nitrate ions and hydronium ions.What change in hybridization of the nitrogen atom occurs in this dissociation?

A) sp² to sp³
B) sp² to sp
C) sp³ to sp
D) sp to sp³
E) no change

Question 32

Which of the following hybridized atoms is not possible?

A) an sp hybridized nitrogen atom
B) an sp² hybridized oxygen atom
C) an sp³ hybridized boron atom
D) an sp³ hybridized phosphorus atom
E) an sp³ hybridized hydrogen atom

Question 33

What is the molecular geometry around a central atom that is sp² hybridized,has three sigma bonds,and one pi bond?

A) trigonal-planar
B) trigonal-pyramidal
C) bent
D) T-shaped
E) tetrahedral

Question 34

Atomic orbitals combine most effectively to form molecular orbitals when

A) electrons in the orbitals have no spins.
B) electrons in the orbitals have the same spin.
C) the atoms have an equal number of valence electrons.
D) the atomic orbitals have similar energies.
E) only d-orbitals are used in bonding.

Question 35

Which of the following concerning $\sigma$ and $\pi$ bonds is/are correct?
1)A sigma bond may be formed from the sideways overlap of two parallel p orbitals.
2)No more than two pi bonds are possible between adjacent carbon atoms.
3)The considerable energy required to rotate pi bonded atoms is the primary reason for geometrical isomerism in some pi bonded molecules.

A) 1 only
B) 2 only
C) 3 only
D) 1 and 2
E) 2 and 3

Question 36

Which of the labeled carbon atoms (C₁-C₄)is/are sp hybridized?

A) C₁
B) C₁ and C₂
C) C₃
D) C₂ and C₄
E) C₁ and C₃

Question 37

When an atom in a molecule or ion is described as sp³ hybridized,its electron pair geometry is

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

Question 38

A molecular orbital that decreases the electron density between two nuclei is said to be ____.

A)hybridized
B)bonding
B)antibonding
D)pi-bonding
E)nonpolar

Question 39

What is the molecular geometry around an atom that has 2 $\sigma$ bonds,0 $\pi$ bonds,and 1 lone pair of electrons?

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

Question 40

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.According to molecular orbital theory,which of the following species will have the $\underline{\text{ highest }}$ bond order?

A) B₂⁺
B) H₂
C) F₂⁺
D) N₂⁺
E) O₂^2-

Question 41

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.Consider the molecules B₂,C₂,N₂ and F₂.Which two molecules have the same bond order?

A) B₂ and C₂
B) B₂ and F₂
C) C₂ and N₂
D) C₂ and F₂
E) N₂ and F₂

Question 42

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.According to molecular orbital theory,which of the following species will have only $\underline{\text{ one }}$ unpaired electron?

A) B₂
B) O₂^2-
C) C₂
D) O₂
E) N₂⁺

Question 43

Which molecule will have the following valence molecular orbital level energy diagram?

A) Li₂
B) Be₂
C) B₂
D) C₂
E) N₂

Question 44

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to diagram 9-1.Identify the molecule with the shortest bond length.

A) O₂
B) C₂
C) B₂
D) F₂
E) N₂

Question 45

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.Assuming that the molecular orbital energy diagram for a homonuclear diatomic molecule applies to a heteronuclear diatomic molecule,determine which of the following species is paramagnetic.

A) NO⁺
B) CO
C) CN^-
D) OF^-
E) NO

Question 46

What is the bond order for a molecule with 6 electrons in bonding molecular orbitals and 6 electrons in antibonding molecular orbitals?

A) 0
B) 0.5
C) 1
D) 1.5
E) 2

Question 47

What does the following figure represent?

A) the overlap of two 1s orbitals to form a $\sigma$ bond
B) the overlap of two 2p orbitals to form a $\sigma$ bond
C) the overlap of two 2p orbitals to form a $\pi$ bond
D) the overlap of a 1s orbital and a 2p orbital to form a $\sigma$ bond
E) the overlap of a 1s orbital and a 2p orbital to form a $\pi$ bond

Question 48

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.Assume that the molecular orbital energy diagram for a homonuclear diatomic molecule applies to a heteronuclear diatomic molecule.What is the molecular orbital configuration of CO?

A) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁴ ( $\sigma$ _2p)²
B) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)² ( $\sigma$ _2p)² ( $\pi$ *_2p)²
C) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)² ( $\sigma$ _2p)⁴
D) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁶
E) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)³ ( $\sigma$ _2p)³

Question 49

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.According to molecular orbital theory,what is the bond order of C₂⁺?

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

Question 50

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.What is the molecular orbital configuration of N₂²⁺?

A) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁴ ( $\sigma$ _2p)² ( $\pi$ *_2p)²
B) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁴
C) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)² ( $\sigma$ sub>2p)²
D) [core electrons] ( $\sigma$ _2s)⁴ ( $\sigma$ *_2s)⁴
E) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁴ ( $\sigma$ _2p)² ( $\pi$ *_2p)⁴

Question 51

If 10 orbitals on one atom overlap 10 orbitals on a second atom,how many molecular orbitals will form?

A) 1
B) 2
C) 10
D) 20
E) none of these

Question 52

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to diagram 9-1.Identify the molecule or ion with the longest bond length.

A) O₂
B) O₂⁺
C) O₂^-
D) O₂^2-
E) O₂²⁺

Question 53

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.What is the molecular orbital configuration of F₂?

A) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁴ ( $\sigma$ _2p)² ( $\sigma$ *_2p)²
B) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)² ( $\sigma$ _2p)² ( $\sigma$ *_2p)²
C) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁴ ( $\pi$ *_2p)⁴
D) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁴ ( $\sigma$ _2p)² ( $\sigma$ *_2p)⁶
E) [core electrons] ( $\sigma$ _2s)² ( $\sigma$ *_2s)² ( $\pi$ _2p)⁴ ( $\sigma$ _2p)² ( $\pi$ *_2p)⁴

Question 54

The electron configuration of a particular diatomic species is:
[core electrons]( $\sigma$ _2s)²( $\sigma$ *_2s)²( $\sigma$ _2p)²( $\pi$ _2p)²( $\pi$ *_2p)⁰
What is the bond order for this species?

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

Question 55

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.According to molecular orbital theory,which of the following lists ranks the fluorine species in terms of increasing bond order?

A) F₂²⁺ < F₂^2- < F₂
B) F₂^2- < F₂ < F₂²⁺
C) F₂ < F₂²⁺ < F₂^2-
D) F₂ < F₂^2- < F₂²⁺
E) F₂²⁺ < F₂ < F₂^2-

Question 56

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.Assuming that the molecular orbital energy diagram for a homonuclear diatomic molecule applies to a heteronuclear diatomic molecule,determine which of the following species has the highest bond order.

A) NO^-
B) OF^-
C) C₂
D) O₂^2-
E) NO⁺

Question 57

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.According to molecular orbital theory,what is the bond order of Li₂²⁺?

A) 0
B) 0.5
C) 1
D) 1.5
E) 2

Question 58

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.According to molecular orbital theory,which of the following species will have the $\underline{\text{ lowest }}$ bond order?

A) B₂⁺
B) Ne₂²⁺
C) C₂⁺
D) O₂²⁺
E) B₂

Question 59

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.According to molecular orbital theory,which of the following species will be diamagnetic?

A) He₂⁺
B) F₂^-
C) Li₂⁺
D) F₂
E) C₂⁺

Question 60

Diagram 9-1 The molecular orbital diagram below may be used for the following problem(s).For oxygen and fluorine,the $\sigma$ _2p orbital should be lower in energy than the $\pi$ _2p orbitals.However,the diagram will still yield correct bond order and magnetic behavior for these molecules.

-Refer to Diagram 9-1.According to molecular orbital theory,which of the following species will be paramagnetic?

A) O₂^2-
B) Li₂
C) O₂^-
D) C₂
E) F₂

Question 61

The following valence molecular orbital energy level diagram is appropriate for which one of the listed species?

A) B₂²⁺
B) C₂²⁺
C) N₂²⁺
D) O₂²⁺
E) F₂²⁺

Question 62

In the NO₂^- ion,each atom can be viewed as sp² hybridized.Thus,each atom has one remaining unhybridized p orbital.How many $\pi$ _2p molecular orbitals (including both bonding and antibonding orbitals)are formed using the unhybridized p orbitals?

A) 1
B) 3
C) 4
D) 6
E) 12

Question 63

SF₃⁺,has a tetrahedral electron-pair geometry and a trigonal-pyramidal molecular geometry.The hybridization of the central sulfur atom is ________.

Question 64

In valence bond theory,each sigma bond in CH₄ is formed from the overlap of a hydrogen atom's 1s orbital with a(n)________ hybridized orbital on the carbon atom.

Question 65

The hybridization of the carbon atom in CF₃⁺ is ________.

Question 66

In HF₂^- the hydrogen is shared between the two fluorine atoms.Which theory,valence bond or molecule orbital,correctly accounts for this three-center bonding?

Question 67

In molecular orbital theory,the bond order is defined as 1/2 $\times$ (the number of electrons in ________ orbitals minus the number of electrons in antibonding orbitals).

Question 68

Draw a Lewis structure of xenon trioxide.What is the hybridization of the xenon atom in this molecule?

Question 69

Which molecule will have the following valence molecular orbital energy level diagram?

A) Be₂
B) B₂
C) C₂
D) N₂
E) O₂

Question 70

Which diatomic molecule or ion has valence electron molecular orbital configuration provided below?
[core electrons]( $\sigma$ _2s)²( $\sigma$ *_2s)²( $\sigma$ _2p)²( $\pi$ _2p)⁴( $\pi$ *_2p)¹

A) C₂
B) O₂⁺
C) O₂⁺.
D) Ne₂
E) H₂

Question 71

Benzene,C₆H₆,consists of a six member ring of sp² hybridized carbon atoms.Each carbon atom has one unhybridized p orbital.How many $\pi$ _2p bonding,antibonding,and nonbonding molecular orbitals exist for benzene?

A) Three $\pi$ _2p molecular orbitals exist; two bonding and one antibonding.
B) Three $\pi$ _2p molecular orbitals exist; one bonding,one antibonding,and one nonbonding.
C) Six $\pi$ _2p molecular orbitals exist; three bonding and three antibonding.
D) Six $\pi$ _2p molecular orbitals exist; two bonding,two nonbonding,and two antibonding.
E) Twelve $\pi$ _2p molecular orbitals exist; six bonding and six antibonding.

Question 72

Which theory,valence bond or molecule orbital,correctly predicts the existence of paramagnetic molecules?