Deck 9: Covalent Bonding: Orbitals

Question 1

Consider the molecule and the following hybridization choices:
What is the hybridization of the carbon atom that is bonded to chlorine?

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Answer 1

sp³

Question 2

Consider the following Lewis structure: Which statement about the molecule is false?

A)There are 10 sigma and 2 pi bonds.
B)C-2 is sp² hybridized with bond angles of 120°.
C)Oxygen is sp³ hybridized.
D)This molecule contains 28 valence electrons.
E)There are some H-C-H bond angles of about 109° in the molecule.

Answer 2

Oxygen is sp³ hybridized.

Question 3

Consider the molecule and the following hybridization choices:
What is the hybridization of the carbon atom that is double-bonded to oxygen?

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Answer 3

sp²

Question 4

The hybridization of the central atom in I₃^- is:

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 5

The hybridization of the central atom in XeF₅⁺ is:

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 6

The hybridization of I in IF₄^- is

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 7

Consider the molecule and the following hybridization choices:
What is the hybridization of the oxygen atom?

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 8

Consider the molecule and the following hybridization choices:
What is the hybridization of the nitrogen atom?

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 9

The hybridization of Cl in ClF₂⁺ is

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 10

The hybridization of the carbon atom in the cation CH₃⁺ is:

A)sp²
B)sp³
C)dsp
D)sp
E)none of these

Question 11

Atoms that are sp² hybridized form ____ pi bond(s).

A)0
B)1
C)2
D)3
E)4

Question 12

Consider the following Lewis structure: What is the hybridization of the atoms O,C-1,C-2,and C-4?

A)sp³ sp³ sp sp²
B)sp sp³ sp sp
C)sp sp² sp sp²
D)sp² sp³ sp² sp³
E)sp³ sp sp sp²
O C-1 C-2 C-4

Question 13

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

A)H₂CO
B)CO₂
C)C₂H₄
D)C₂H₆
E)All of the above (A-D)contain at least one pi bond.

Question 14

The hybridization of the central atom in O₃ is:

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 15

Which statement about N₂ is false?

A)It is a gas at room temperature.
B)The oxidation state is +3 on one N and -3 on the other.
C)It has one sigma and two pi bonds between the two atoms.
D)It can combine with H₂ to form NH₃.
E)It has two pairs of nonbonding electrons.

Question 16

Which of the following molecules contains a central atom with sp² hybridization?

A)
B)
C)
D)
E)

Question 17

The hybridization of the central atom,Al,in AlBr₃ is

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 18

The hybridization of the central atom in ClF₂⁺ is:

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 19

What hybridization is predicted for the nitrogen atom in the NO₃^- ion?

A)sp²
B)sp³
C)dsp³
D)d²sp³
E)none of these

Question 20

In the molecule C₂H₄ the valence orbitals of the carbon atoms are assumed to be

A)not hybridized
B)sp hybridized
C)sp² hybridized
D)sp³ hybridized
E)dsp hybridized

Question 21

The hybridization of Se in SeF₆ is

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 22

Tetracyanoethylene has the skeleton shown below: From its Lewis structure determine the following:
How many sigma and pi bonds are in the molecule?

A)4 sigma and 5 pi
B)6 sigma and 8 pi
C)9 sigma and 8 pi
D)9 sigma and 9 pi
E)5 sigma and 8 pi

Question 23

Consider the molecule C₂H₄.The hybridization of each C atom is

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 24

Which of the following substances contains two pi bonds?

A)C₂H₄
B)C₃H₈
C)C₂H₂
D)C₂H₆
E)CH₄

Question 25

Tetracyanoethylene has the skeleton shown below: From its Lewis structure determine the following:
How many of the atoms are sp² hybridized?

A)2
B)4
C)6
D)8
E)10

Question 26

Consider the skeletal structure shown below:
N-C-C-N
Draw the Lewis structure and answer the following:
How many pi bonds does the molecule contain?

A)0
B)2
C)4
D)6
E)7

Question 27

Tetracyanoethylene has the skeleton shown below: From its Lewis structure determine the following:
How many nonbonded electron pairs are in the molecule?

A)0
B)2
C)4
D)5
E)8

Question 28

The hybridization of Br in BrF₃ is

A)sp
B)sp²
C)sp³
D)dsp³
E)d²sp³

Question 29

Complete the Lewis structure for the following molecule: This molecule has __________ sigma and __________ pi bonds.

A)4,5
B)6,3
C)11,5
D)13,2
E)13,3

Question 30

Tetracyanoethylene has the skeleton shown below: From its Lewis structure determine the following:
How many of the atoms are sp hybridized?

A)2
B)4
C)6
D)8
E)10

Question 31

The hybridization of the central atom in NO₃^- is

A)p³
B)sp²
C)sp³
D)sp
E)dsp²

Question 32

Use the molecules below to answer the next three questions.

-Which molecule(s)have p orbitals that share an electron pair to create $\pi$ bonding?

A)I
B)II
C)III
D)all of the above
E)none of the above

Question 33

Whenever a set of equivalent tetrahedral atomic orbitals is required,an atom will adopt a set of sp³ orbitals.

Question 34

Use the molecules below to answer the next three questions.
Which molecule(s)have equivalent C-C bonds throughout the molecule?

A)I
B)II
C)III
D)all of the above
E)none of the above

Question 35

When a carbon atom has sp³ hybridization,it has

A)four $\pi$ bonds
B)three $\pi$ bonds and one $\sigma$ bond
C)two $\pi$ bonds and two $\sigma$ bonds
D)one $\pi$ bond and three $\sigma$ bonds
E)four $\sigma$ bonds

Question 36

Consider the skeletal structure shown below:
N-C-C-N
Draw the Lewis structure and answer the following:
How many of the atoms are sp hybridized?

A)0
B)1
C)2
D)3
E)4

Question 37

Use the molecules below to answer the next three questions.
Which molecule(s)have at least one carbon atom that is sp hybridized?

A)I
B)II
C)III
D)all of the above
E)none of the above

Question 38

The hybridization of the B in BH₃ is sp³.

Question 39

The hybridization of the lead atom in PbCl₄ is

A)dsp²
B)sp²
C)d²sp³
D)dsp³
E)none of these

Question 40

A $\pi$ (pi)bond is the result of the

A)overlap of two s orbitals
B)overlap of an s orbital and a p orbital
C)overlap of two p orbitals along their axes
D)sidewise overlap of two parallel p orbitals
E)sidewise overlap of two s orbitals

Question 41

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

A)1
B)4
C)8
D)16
E)none of these

Question 42

If a molecule demonstrates paramagnetism,then :
I.The substance can have both paired and unpaired electrons.
II.The bond order is not a whole number.
III.It can be determined by drawing a Lewis structure.
IV.It must be an ion.

A)I,II
B)I,II,IV
C)II,III
D)I only
E)All of the above are correct.

Question 43

Which of the following species is paramagnetic?

A)C₂
B)O₂
C)F₂
D)Li₂
E)none of these

Question 44

Which of the following species has the largest dissociation energy?

A)O₂
B)O₂^-
C)O₂^2-
D)O₂⁺
E)O₂²⁺

Question 45

Which of the following diatomic molecules has a bond order of 2?

A)B₂
B)C₂
C)P₂
D)F₂
E)Li₂

Question 46

For how many of the following does the bond order decrease if you add one electron to the neutral molecule? B₂,C₂,P₂,F₂

A)0
B)1
C)2
D)3
E)4

Question 47

Order the following from shortest to longest bond: C₂,B₂,H₂,N₂

A)H₂,N₂,C₂,B₂
B)N₂,C₂,B₂,H₂
C)C₂,N₂,H₂,B₂
D)C₂,B₂,H₂,N₂
E)none of these

Question 48

Which of the following has the largest bond order?

A)N₂
B)N₂^-
C)N₂^2-
D)N₂⁺
E)N₂²⁺

Question 49

As the bond order of a bond increases,the bond energy ______ and the bond length ______.

A)increases,increases
B)decreases,decreases
C)increases,decreases
D)decreases,increases
E)More information is needed to answer this question.

Question 50

Larger bond order means greater bond strength.

Question 51

When an electron pair is shared in the area centered on a line joining the atoms,a $\sigma$ (sigma)bond is formed.

Question 52

The electron configuration of a particular diatomic species is ( $\sigma$ _2s)²( $\sigma$ *_2s)²( $\sigma$ _2p)²( $\pi$ _2p)⁴( $\pi$ *_2p)².What is the bond order for this species?

A)3.5
B)3
C)2.5
D)2
E)1.5

Question 53

The hybridization of a molecule is measured to determine the shape of the molecule.

Question 54

The configuration ( $\sigma$ _2s)²( $\sigma$ _2s*)²( $\pi$ _2py)¹( $\pi$ _2px)¹ is the molecular orbital description for the ground state of

A)Li₂⁺
B)Be₂
C)B₂
D)B₂^2-
E)C₂

Question 55

Which charge(s)on an O₂ ion would give a bond order of 2.5?

A)-2
B)-1
C)+1
D)two of these
E)none of these

Question 56

What is the bond order of He₂⁺?

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

Question 57

The fact that O₂ is paramagnetic can be explained by

A)the Lewis structure of O₂
B)resonance
C)a violation of the octet rule
D)the molecular orbital diagram for O₂
E)hybridization of atomic orbitals in O₂

Question 58

For which of the following diatomic molecules would the bond order become greater if an electron is removed (i.e. ,if the molecule is converted to the positive ion in its ground state)?

A)B₂
B)C₂
C)P₂
D)F₂
E)Na₂

Question 59

When comparing Be₂ and H₂:
I.Be₂ is more stable because it contains both bonding and antibonding valence electrons.
II.H₂ has a higher bond order than Be₂.
III.H₂ is more stable because it only contains $\sigma$ _1s electrons.
IV.H₂ is more stable because it is diamagnetic,whereas Be₂ is paramagnetic.

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

Question 60

How many of the following: F₂,B₂,O₂,N₂ ,are paramagnetic?

A)0
B)1
C)2
D)3
E)4

Question 61

According to MO theory,F₂ should be diamagnetic.

Question 62

The H₂^- ion is more stable than H₂ since it has an additional electron to produce a net lowering of energy.

Question 63

Which of the following has the greatest bond strength?

A)B₂
B)O₂^-
C)CN^-
D)O₂⁺
E)NO^-

Question 64

Which of the following statements is false?

A)C₂ is paramagnetic.
B)C₂ is diamagnetic.
C)The carbon-carbon bond in C₂^2- is stronger than the one in CH₃CH₃.
D)The carbon-carbon bond in C₂^2- is shorter than the one in CH₃CH₃.
E)Two of the above.

Question 65

Which of the following statements about the species CN^- is false?

A)It is paramagnetic.
B)The total number of electrons is 14.
C)Its bond order is 3.
D)It has two pi bonds.
E)All of these are true.

Question 66

In the molecular orbital description of CO:

A)The highest energy electrons occupy antibonding orbitals.
B)Six molecular orbitals contain electrons.
C)There are two unpaired electrons.
D)The bond order is 3.
E)All of the above are false.

Question 67

A species has the following MO configuration: ( $\sigma$ _1s)²( $\sigma$ _1s*)²( $\sigma$ _2s)²( $\sigma$ _2s*)²( $\sigma$ _2p)²( $\pi$ _2p)²
This substance is

A)paramagnetic with one unpaired electron
B)paramagnetic with two unpaired electrons
C)paramagnetic with three unpaired electrons
D)paramagnetic with four unpaired electrons
E)diamagnetic

Question 68

Which of the following statements about the molecule BN is false?

A)It is paramagnetic.
B)Its bond order is 2.
C)The total number of electrons is 12.
D)It has two pi bonds.
E)All of these are true.

Question 69

Which of the following electron distributions among the molecular orbitals best describes the NO molecule?

Question 70

How many unpaired electrons in the F₂²⁺ ion are based on molecular orbital theory? The order of the molecular orbitals are ( $\sigma$ _2s)( $\sigma$ *_2s)( $\sigma$ _2p)( $\pi$ _2p)( $\pi$ *_2p)( $\sigma$ *_2p).

A)0
B)1
C)2
D)3
E)4

Question 71

Consider the molecular orbital description of the NO^- anion.Which of the following statements is false?

A)NO^- is paramagnetic.
B)NO^- is isoelectronic with CO.
C)The bond energy in NO⁺ is greater than the bond energy in NO^-.
D)The bond order in NO^- is 2.
E)Statements A through D are false.

Question 72

What is the bond order of Ne₂?

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

Question 73

Which of the nitrogen-containing molecules below is paramagnetic in its lowest energy state?

A)N₂
B)NO
C)NH₃
D)N₂H₄
E)none of these

Question 74

For how many of the following does bond order decrease if you take away one electron from the neutral molecule? B₂,C₂,P₂,F₂

A)0
B)1
C)2
D)3
E)4

Question 75

Which of the following statements is incorrect?

A)For the molecule NO,the molecular orbital model is preferred over the localized electron model because NO contains an unpaired electron.
B)Electrons in antibonding orbitals will cause a molecule to be paramagnetic.
C)According to the molecular orbital model,when bonding occurs between hydrogen and bromine to make HBr,the 1s orbital of the hydrogen atom no longer exists.
D)Antibonding electrons are higher in energy than the atomic orbitals from which they came.
E)At least two of the above are incorrect.

Question 76

Which of the following molecules or ions is not paramagnetic in its ground state?

A)O₂
B)O₂⁺
C)B₂
D)NO
E)F₂

Question 77

Which of the following has a bond order of 1.5?

A)O₂⁺
B)N₂
C)O₂^-
D)C₂
E)none of these

Question 78

Paramagnetism is associated with paired electrons.

Question 79

What is the bond order of C₂⁺?

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

Question 80

Which of the following has the shortest bond length?

A)O₂^2-
B)O₂
C)O₂^-
D)O₂⁺
E)Two of these have the shortest bond length.