Question 1

According to valence bond theory, the triple bond in ethyne (acetylene, C2H2) consists of

Accepted Answer

A) three σ bonds and no π bonds. 
B) two σ bonds and one π  bond. 
C) one σ bond and twoπ bonds. 
D) no σ bonds and three π  bonds. 
E) None of these choices are correct. 
A) three σ bonds and no π bonds. 
B) two σ bonds and one π  bond. 
C) one σ bond and twoπ bonds. 
D) no σ bonds and three π  bonds. 
E) None of these choices are correct. C

Question 2

Valence bond theory predicts that carbon will use __________ hybrid orbitals in the carbonate anion, CO3−.

Accepted Answer

A) sp 
B) sp 2 
C) sp 3 
D) sp 3 d 
E) sp 3 d 2 
A) sp 
B) sp 2 
C) sp 3 
D) sp 3 d 
E) sp 3 d 2 B

Question 3

A carbon-carbon triple bond in a molecule may give rise to the existence of cis and trans isomers.

Accepted Answer

A) True 
 B)False  False

Question 4

Carbon uses __________ hybrid orbitals in ClCN.

Accepted Answer

A) sp 
B) sp 2 
C) sp 3 
D) sp 3 d 
E) sp 3 d 2 
A) sp 
B) sp 2 
C) sp 3 
D) sp 3 d 
E) sp 3 d 2

Question 5

The angles between sp2 hybrid orbitals are 109.5°.

Accepted Answer

A) True 
 B)False

Question 6

According to the molecular orbital (MO) treatment of the NO molecule, what are the bond order and the number of unpaired electrons, respectively?

Accepted Answer

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

Question 7

According to molecular orbital (MO) theory, the twelve outermost electrons in the O2 molecule are distributed as follows:

Accepted Answer

A) 12 in bonding MOs, 0 in antibonding MOs. 
B) 10 in bonding MOs, 2 in antibonding MOs. 
C) 9 in bonding MOs, 3 in antibonding MOs. 
D) 8 in bonding MOs, 4 in antibonding MOs. 
E) 7 in bonding MOs, 5 in antibonding MOs. 
A) 12 in bonding MOs, 0 in antibonding MOs. 
B) 10 in bonding MOs, 2 in antibonding MOs. 
C) 9 in bonding MOs, 3 in antibonding MOs. 
D) 8 in bonding MOs, 4 in antibonding MOs. 
E) 7 in bonding MOs, 5 in antibonding MOs.

Question 8

A molecule with the formula AX3 uses __________ to form its bonds.

Accepted Answer

A) sp hybrid orbitals 
B) sp 2 hybrid orbitals 
C) sp 3 hybrid orbitals 
D) sp 3 d hybrid orbitals 
E) sp 3 d 2 hybrid orbitals 
A) sp hybrid orbitals 
B) sp 2 hybrid orbitals 
C) sp 3 hybrid orbitals 
D) sp 3 d hybrid orbitals 
E) sp 3 d 2 hybrid orbitals

Question 9

Atoms of period 3 and beyond can undergo sp3d2 hybridization, but atoms of period 2 cannot.

Accepted Answer

A) True 
 B)False

Question 10

According to molecular orbital theory, all diatomic molecules with an even number of electrons will be diamagnetic.

Accepted Answer

A) True 
 B)False

Question 11

A carbon-carbon double bond in a molecule may give rise to the existence of cis and trans isomers.

Accepted Answer

A) True 
 B)False

Question 12

Which one of the following statements about orbital hybridization is incorrect?

Accepted Answer

A) The carbon atom in CH4 is sp 3 hybridized. 
B) The carbon atom in CO 2 is sp hybridized. 
C) The nitrogen atom in NH 3 is sp 2 hybridized. 
D) sp 2 hybrid orbitals are coplanar, and at 120° to each other. 
E) sp hybrid orbitals lie at 180° to each other. 
A) The carbon atom in CH4 is sp 3 hybridized. 
B) The carbon atom in CO 2 is sp hybridized. 
C) The nitrogen atom in NH 3 is sp 2 hybridized. 
D) sp 2 hybrid orbitals are coplanar, and at 120° to each other. 
E) sp hybrid orbitals lie at 180° to each other.

Question 13

According to molecular orbital theory, what is the bond order in the O2+ ion?

Accepted Answer

A) 5.5 
B) 5 
C) 4 
D) 2.5 
E) 1.5 
A) 5.5 
B) 5 
C) 4 
D) 2.5 
E) 1.5

Question 14

Determine the shape (geometry) of PCl3 and then decide on the appropriate hybridization of phosphorus in this molecule. (Phosphorus is the central atom.)

Accepted Answer

A) sp 3 
B) sp 2 
C) sp 
D) sp 3 d 
E) sp 3 d 2 
A) sp 3 
B) sp 2 
C) sp 
D) sp 3 d 
E) sp 3 d 2

Question 15

Which one, if any, of the following statements about the MO treatment of the bonding in benzene is correct?

Accepted Answer

A) MO theory uses resonance to describe the delocalized nature of the bonding in benzene. 
B) The lowest energy pi-bonding orbital in benzene can hold up to 6 electrons. 
C) MO theory predicts that benzene should be paramagnetic. 
D) The lowest energy pi-bonding MO in benzene has two hexagonal lobes, above and below the plane of the carbon atoms. 
E) None of these choices are correct. 
A) MO theory uses resonance to describe the delocalized nature of the bonding in benzene. 
B) The lowest energy pi-bonding orbital in benzene can hold up to 6 electrons. 
C) MO theory predicts that benzene should be paramagnetic. 
D) The lowest energy pi-bonding MO in benzene has two hexagonal lobes, above and below the plane of the carbon atoms. 
E) None of these choices are correct.

Question 16

When PCl5 solidifies it forms PCl4+ cations and PCl6-anions. According to valence bond theory, what hybrid orbitals are used by phosphorus in the PCl4+ cations?

Accepted Answer

A) sp 
B) sp 2 
C) sp 3 
D) sp 3 d 
E) sp 3 d 2 
A) sp 
B) sp 2 
C) sp 3 
D) sp 3 d 
E) sp 3 d 2

Question 17

Valence bond theory predicts that tin will use __________ hybrid orbitals in SnF5−.

Accepted Answer

A) sp 2 
B) sp 3 
C) sp 3 d 
D) sp 3 d 2 
E) d 2 sp 3 
A) sp 2 
B) sp 3 
C) sp 3 d 
D) sp 3 d 2 
E) d 2 sp 3

Question 18

A molecule with the formula AX4E uses __________ to form its bonds.

Accepted Answer

A) sp 2 hybrid orbitals 
B) sp 3 hybrid orbitals 
C) sp 3 d hybrid orbitals 
D) sp 3 d 2 hybrid orbitals 
E) None of these choices are correct. 
A) sp 2 hybrid orbitals 
B) sp 3 hybrid orbitals 
C) sp 3 d hybrid orbitals 
D) sp 3 d 2 hybrid orbitals 
E) None of these choices are correct.

Question 19

According to valence bond theory, overlap of bonding orbitals of atoms will weaken a bond, due to electron-electron repulsion.

Accepted Answer

A) True 
 B)False

Question 20

In applying molecular orbital theory, the bond order is calculated in the same way as with Lewis structures.

Accepted Answer

A) True 
 B)False

Exam 11: Theories of Covalent Bonding

According to valence bond theory, the triple bond in ethyne (acetylene, C2H2) consists of

Valence bond theory predicts that carbon will use __________ hybrid orbitals in the carbonate anion, CO3−.

A carbon-carbon triple bond in a molecule may give rise to the existence of cis and trans isomers.

Carbon uses __________ hybrid orbitals in ClCN.

The angles between sp2 hybrid orbitals are 109.5°.

According to the molecular orbital (MO) treatment of the NO molecule, what are the bond order and the number of unpaired electrons, respectively?

According to molecular orbital (MO) theory, the twelve outermost electrons in the O2 molecule are distributed as follows:

A molecule with the formula AX3 uses __________ to form its bonds.

Atoms of period 3 and beyond can undergo sp3d2 hybridization, but atoms of period 2 cannot.

According to molecular orbital theory, all diatomic molecules with an even number of electrons will be diamagnetic.

A carbon-carbon double bond in a molecule may give rise to the existence of cis and trans isomers.

Which one of the following statements about orbital hybridization is incorrect?

According to molecular orbital theory, what is the bond order in the O2+ ion?

Determine the shape (geometry) of PCl3 and then decide on the appropriate hybridization of phosphorus in this molecule. (Phosphorus is the central atom.)

Which one, if any, of the following statements about the MO treatment of the bonding in benzene is correct?

When PCl5 solidifies it forms PCl4+ cations and PCl6-anions. According to valence bond theory, what hybrid orbitals are used by phosphorus in the PCl4+ cations?

Valence bond theory predicts that tin will use __________ hybrid orbitals in SnF5−.

A molecule with the formula AX4E uses __________ to form its bonds.

According to valence bond theory, overlap of bonding orbitals of atoms will weaken a bond, due to electron-electron repulsion.

In applying molecular orbital theory, the bond order is calculated in the same way as with Lewis structures.

Keys to the Study of Chemistry: Definitions, Units, and Problem Solving

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

Models of Chemical Bonding

The Shapes of Molecules

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and Reaction Direction

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

According to valence bond theory, the triple bond in ethyne (acetylene, C₂H₂) consists of

Valence bond theory predicts that carbon will use __________ hybrid orbitals in the carbonate anion, CO₃⁻.

The angles between sp² hybrid orbitals are 109.5°.

According to molecular orbital (MO) theory, the twelve outermost electrons in the O₂ molecule are distributed as follows:

A molecule with the formula AX₃ uses __________ to form its bonds.

Atoms of period 3 and beyond can undergo sp³d² hybridization, but atoms of period 2 cannot.

According to molecular orbital theory, what is the bond order in the O₂⁺ ion?

Determine the shape (geometry) of PCl₃ and then decide on the appropriate hybridization of phosphorus in this molecule. (Phosphorus is the central atom.)

When PCl₅solidifies it forms PCl₄⁺ cations and PCl₆^-anions. According to valence bond theory, what hybrid orbitals are used by phosphorus in the PCl₄⁺ cations?

Valence bond theory predicts that tin will use __________ hybrid orbitals in SnF₅⁻.

A molecule with the formula AX₄E uses __________ to form its bonds.