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

Question 1

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

Answer 1

thirteen sigma bonds and one pi bond

Question 2

What is the hybridization of the nitrogen atom in NO+?

A) sp
B) sp²
C) sp³
D) none

Answer 2

sp³

Question 3

How many sigma (σ) bonds and pi (π) bonds are in dioxygen?

A) three σ, zero π
B) two σ, one π
C) two σ, two π
D) one σ, two π
E) one σ, one π

Answer 3

one σ, two π

Question 4

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

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

Question 5

What is the hybridization of the sulfur atom in SCl₂?

A) sp
B) sp²
C) sp³
D) sp4
E) None of these

Question 6

Which of the following does not contain at least one pi bond?

A) H_N
B) C₃H₈
C) CO₂
D) N₂H₂
E) All of them have one or more pi bonds.

Question 7

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 8

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 9

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 10

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 11

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

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

Question 12

How many sigma (σ) bonds and pi (π) bonds are present in the given molecule?

A) Seven σ and three π
B) Seven σ and two π
C) Five σ and five π
D) Five σ and three π
E) Five σ and two π

Question 13

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

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

Question 14

The hybridization of the nitrogen atom in NH₃ is _____.

A) sp
B) sp²
C) sp³
D) sp⁴
E) sp⁶

Question 15

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 16

What is the hybridization of an atom that has 3 σ bonds, 0 π bonds, and 0 lone pair?

A) sp
B) sp²
C) sp³
D) sp⁴
E) none

Question 17

What is the molecular geometry around an atom that has 2 σ bonds, 2 π bonds, and 0 lone pair of electrons?

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

Question 18

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^-

Question 19

In the context of valence shell electron pair repulsion (VSEPR) theory, 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 20

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

A) sp
B) sp²
C) sp³
D) none

Question 21

Refer to Diagram 9-1. According to molecular orbital theory, what is the bond order of Ne₂2+?

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

Question 22

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

A) O₂
B) C₂+
C) F₂-
D) H₂
E) Li₂+

Question 23

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

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

Question 24

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 25

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

A) Li₂
B) C₂
C) C₂-
D) F₂
E) O₂2+

Question 26

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

A) C₂
B) Ne₂2+
C) O₂2-
D) N2
E) O₂+

Question 27

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

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

Question 28

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 29

Refer to Diagram 9-1. According to molecular orbital theory, what is the bond order of O₂-?

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

Question 30

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 31

What is the hybridization of oxygen atom O?

A) sp
B) sp²
C) sp³
D) sp⁴
E) none

Question 32

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 33

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 34

Which of the underlined atoms (C₁, C₂, N, and O) are sp² hybridized?

A) N and O
B) C1 and N
C) C1 and O
D) C2 and N
E) C1 and C2

Question 35

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 36

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 37

Refer to Diagram 9-1. According to molecular orbital theory, which of the following species will have the lowest bond order?

A) He₂+
B) H₂
C) C₂+
D) F₂2+
E) F₂

Question 38

Refer to Diagram 9-1. According to molecular orbital theory, which of the following species will have the highest bond order?

A) H₂-
B) Li₂
C) C₂+
D) N₂
E) H₂

Question 39

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 40

Which of the following hybridized atoms is impossible to form?

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 41

Which diatomic molecule or ion has valence electron molecular orbital configuration provided below? [core electrons](σ_2s)²(σ*_2s)²(σ_2p)²(π_2p)⁴(π*_2p)³

A) B₂
B) O₂-
C) O₂²⁺
D) Ne₂
E) Li₂

Question 42

If 7 orbitals on one atom overlap 7 orbitals on a second atom, how many molecular orbitals will be formed?

A) 1
B) 2
C) 7
D) 14
E) None of these

Question 43

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 44

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

What does the following figure represent?

A) the overlap of two 1s orbitals to form a σ bond
B) the overlap of two 2p orbitals to form a σ bond
C) the overlap of two 2p orbitals to form a π bond
D) the overlap of a 1s orbital and a 2p orbital to form a σ bond
E) the overlap of a 1s orbital and a 2p orbital to form a π bond

Question 46

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] (σ_2s)² (σ*_2s)² (π_2p)⁴ (σ_2p)²
B) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)² (σ_2p)² (π*_2p)²
C) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)² (σ_2p)⁴
D) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)⁶
E) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)³ (σ_2p)³

Question 47

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

Question 48

Which of the following molecules has the below valence molecular orbital energy level diagram? σ*_2p
Π*_2p
Σ_2p
↑↓
Π_2p
↑↓
↑↓
Σ*_2s
↑↓
Σ_2s
↑↓

A) Li₂
B) Be₂
C) B₂
D) C₂
E) N₂

Question 49

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

Question 50

The electron configuration of a particular diatomic species is: [core electrons](σ_2s)²(σ*_2s)²(σ_2p)²(π_2p)³(π*_2p)⁰
What is the bond order for this species?

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

Question 51

What is the bond order for a molecule with 2 electrons in bonding molecular orbitals and 1 electrons in antibonding molecular orbitals?

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

Question 52

Refer to Diagram 9-1. Which of the following is the correct molecular orbital configuration of F₂?

A) [core electrons] (σ_2s)² (σ*_2s)² (σ_2p)² (π_2p)⁴ (σ*_2p)²
B) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)² (σ_2p)² (π*_2p)²
C) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)⁴ (π*_2p)⁴
D) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)⁴ (σ_2p)² (π*_2p)⁶
E) [core electrons] (σ_2s)² (σ*_2s)² (σ_2p)² (π_2p)⁴ (π*_2p)⁴

Question 53

In the NO₂^- ion, each atom can be viewed as sp² hybridized. Thus, each atom has one remaining unhybridized p orbital. How many π_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 54

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

A) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)⁴ (σ_2p)² (π*_2p)²
B) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)⁴
C) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)² (σ_2p)²
D) [core electrons] (σ_2s)⁴ (σ*_2s)⁴
E) [core electrons] (σ_2s)² (σ*_2s)² (π_2p)⁴ (σ_2p)² (π*_2p)⁴

Question 55

Benzene, C₆H₆, consists of a six member ring of sp² hybridized carbon atoms. Each carbon atom has one unhybridized p orbital. How many π_2p bonding, antibonding, and nonbonding molecular orbitals exist for benzene?

A) Three π_2p molecular orbitals exist; two bonding and one antibonding.
B) Three π_2p molecular orbitals exist; one bonding, one antibonding, and one nonbonding.
C) Six π_2p molecular orbitals exist; three bonding and three antibonding.
D) Six π_2p molecular orbitals exist; two bonding, two nonbonding, and two antibonding.
E) Twelve π_2p molecular orbitals exist; six bonding and six antibonding.

Question 56

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

A) NO⁺
B) CO
C) CN^-
D) OF^-
E) NO

Question 57

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 58

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 59

Which molecule will have the following valence molecular orbital energy level diagram? σ*_2p
Π*_2p
Σ_2p
Π_2p
↑
↑
Σ*_2s
↑↓
Σ_2s
↑↓

A) Be₂
B) B₂
C) C₂
D) N₂
E) O₂

Question 60

The following valence molecular orbital energy level diagram is appropriate for which one of the listed species? σ*_2p
Π*_2p
↑
↑
Σ_2p
↑↓
↑↓
Π_2p
↑↓
Σ*_2s
↑↓
Σ_2s
↑↓

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

Question 61

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

Question 62

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

Question 63

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 64

Which of the following is the bond order of Li₂ molecule?

A) 2
B) 1.5
C) 1
D) 1.7
E) 2.5

Question 65

What is the hybridization of carbon atoms present in acetylene?

A) sp
B) sp²
C) sp³
D) sp⁴
E) sp⁵

Question 66

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