Question 1

Which statement A-D about VSEPR theory is not correct?

Accepted Answer

A) The molecular shape or geometry can differ from the electron-pair geometry. 
B) In VSEPR theory, the shape or geometry of a molecule is determined by electron-electron repulsion. 
C) The steric number of a central atom is the sum of the number of bonds and lone pairs around the atom. 
D) The steric number has five values from 2 to 6. 
E) Statements A-D are all correct. 
A) The molecular shape or geometry can differ from the electron-pair geometry. 
B) In VSEPR theory, the shape or geometry of a molecule is determined by electron-electron repulsion. 
C) The steric number of a central atom is the sum of the number of bonds and lone pairs around the atom. 
D) The steric number has five values from 2 to 6. 
E) Statements A-D are all correct.

Question 2

Which of the following compounds is the most polar?

Accepted Answer

A) NH3 
B) PH3 
C) AsH3 
D) SbH3 
E) BiH3 
A) NH3 
B) PH3 
C) AsH3 
D) SbH3 
E) BiH3

Question 3

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? These molecular orbitals are formed from the 2s and 2p atomic orbitals.   I. Boron nitride is diamagnetic. II. Boron nitride has a bond order of 2.
III) Boron nitride is paramagnetic.
IV) The bond in BNF1F1F1S1F1F1F10 is stronger than the bond in BN.

Accepted Answer

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

Question 4

Which statement A-D regarding semiconductors is not correct?

Accepted Answer

A) An undoped semiconductor does not conduct electricity because it has a filled valence band and a vacant conduction band. 
B) Doping silicon with phosphorous produces an n-type semiconductor. 
C) An n-type semiconductor has electrons in its conduction band. 
D) Doping silicon with gallium removes electrons from the valence band to enhance the conductivity. 
E) Statements A-D all are correct. 
A) An undoped semiconductor does not conduct electricity because it has a filled valence band and a vacant conduction band. 
B) Doping silicon with phosphorous produces an n-type semiconductor. 
C) An n-type semiconductor has electrons in its conduction band. 
D) Doping silicon with gallium removes electrons from the valence band to enhance the conductivity. 
E) Statements A-D all are correct.

Question 5

What angles are present between atoms in a molecule with octahedral geometry?

Accepted Answer

A) 90F1F1F1S1F1F1F10 only 
B) 120F1F1F1S1F1F1F10 only 
C) 180F1F1F1S1F1F1F10 only 
D) 90F1F1F1S1F1F1F10, 180F1F1F1S1F1F1F10 
E) 90F1F1F1S1F1F1F10, 120F1F1F1S1F1F1F10 
A) 90F1F1F1S1F1F1F10 only 
B) 120F1F1F1S1F1F1F10 only 
C) 180F1F1F1S1F1F1F10 only 
D) 90F1F1F1S1F1F1F10, 180F1F1F1S1F1F1F10 
E) 90F1F1F1S1F1F1F10, 120F1F1F1S1F1F1F10

Question 6

Using the energy-level diagram for valence orbitals below, determine the bond order of the PO molecule.

Accepted Answer

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

Question 7

Which one of the statements A-D about electron-pair geometry and molecular geometry is not correct?

Accepted Answer

A) The electron-pair geometry identifies the relative positions of the bonding regions of electrons and the lone pairs of electrons around a central atom in a molecule. 
B) The molecular geometry identifies the relative positions of the atoms around a central atom in a molecule. 
C) If there are no lone pairs, then the electron-pair geometry and the molecular geometry are the same. 
D) The molecular geometry differs from the electron-pair geometry when the number of atoms around the central atom is smaller than the number of regions of electron density. 
E) Statements A-D are all correct. 
A) The electron-pair geometry identifies the relative positions of the bonding regions of electrons and the lone pairs of electrons around a central atom in a molecule. 
B) The molecular geometry identifies the relative positions of the atoms around a central atom in a molecule. 
C) If there are no lone pairs, then the electron-pair geometry and the molecular geometry are the same. 
D) The molecular geometry differs from the electron-pair geometry when the number of atoms around the central atom is smaller than the number of regions of electron density. 
E) Statements A-D are all correct.

Question 8

Oxygen has two common molecular anions: peroxide (O22F1F1F1S1F1F1F10) and superoxide (O2F1F1F1S1F1F1F10). Use the MO energy level diagram below to identify which one of the following statements is not correct. These molecular orbitals are formed from the 2s and 2p atomic orbitals.

Accepted Answer

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. 
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 9

The amide structure is the fundamental linking unit in proteins. Two partial Lewis structures for formamide are shown below. These structures do not show the lone-pair electrons or the formal charges. Experiment shows that formamide is planar, so which is the better representation of the electronic structure, I or II? Is this conclusion consistent with the formal charges on the atoms? Explain the rationale for your answers.

Accepted Answer

Structure II predicts a planar structure

Question 10

What is the hybridization of the bromine atom in BrF5?

Accepted Answer

A) sp3 
B) sp3d 
C) sp3d 2 
D) sp 
E) sp2 
A) sp3 
B) sp3d 
C) sp3d 2 
D) sp 
E) sp2

Question 11

For which of the following molecules is the electron pair geometry octahedral and the molecular geometry square planar?

Accepted Answer

A) SF6 
B) ClF3 
C) XeF4 
D) BrF6 
E) I3F1F1F1S1F1F1F10 
A) SF6 
B) ClF3 
C) XeF4 
D) BrF6 
E) I3F1F1F1S1F1F1F10

Question 12

Which of the following ions is linear?

Accepted Answer

A) SCNF1F1F1S1F1F1F10 
B) NO2F1F1F1S1F1F1F10 
C) SO32F1F1F1S1F1F1F10 
D) NH4F1F1F1S1F1F1F10 
E) SO22F1F1F1S1F1F1F10 
A) SCNF1F1F1S1F1F1F10 
B) NO2F1F1F1S1F1F1F10 
C) SO32F1F1F1S1F1F1F10 
D) NH4F1F1F1S1F1F1F10 
E) SO22F1F1F1S1F1F1F10

Question 13

Which electron-pair geometry corresponds to a steric number of 5?

Accepted Answer

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

Question 14

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

Accepted Answer

A) SO2 
B) OCS 
C) CS2 
D) NH3 
E) CO2 
A) SO2 
B) OCS 
C) CS2 
D) NH3 
E) CO2

Question 15

Which of the following does not represent a F1F1F1S1F1F1F10 bonding molecular orbital?

Accepted Answer

A)    
B)    
C)    
D)    
E) All of the above are F1F1F1S1F1F1F10 bonding orbitals. 
A)    
B)    
C)    
D)    
E) All of the above are F1F1F1S1F1F1F10 bonding orbitals.

Question 16

Formaldehyde has the formula CH2O. The carbon atom has a ________ local molecular geometry and ________ hybridization.

Accepted Answer

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

Question 17

A Lewis structure of aspirin without the nonbonding electrons is shown in the figure below. Taking into account the nonbonding electrons, identify the hybridization of the atomic orbitals for the following atoms: O1, O2, and O3. Identify the bond angles around C1, C2, and O3.

Accepted Answer

O1 is sp³ hybridized, O2 is sp²,

Question 18

In the following reaction, what is the change in geometry of the carbon-containing compound? COCl2(g) F1F1F1S1F1F1F10 H2O(g) F1F1F1S1F1F1F10 CO2(g) F1F1F1S1F1F1F10 2HCl(g)

Accepted Answer

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

Question 19

Both ethane (C2H6) and ethylene (C2H4) have two carbon atoms. In a valence bond picture of the C-C bonds, ________ hybrid orbitals overlap for ethane and ________ hybrid orbitals overlap for ethylene.

Accepted Answer

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

Question 20

In 1995 a Japanese cult attacked the Tokyo subway system with the nerve gas sarin, which focused world attention on the dangers of chemical warfare agents. The connectivity of atoms in the sarin molecule is shown below. Complete the Lewis structure by adding bonds and lone pairs as necessary. Assign formal charges to the P and O atoms, and determine the local molecular geometry around the central oxygen atom.

Accepted Answer

@#IMG-DLM& The formal charges are all 0.

Which statement A-D about VSEPR theory is not correct?

Which of the following compounds is the most polar?

Which statement A-D regarding semiconductors is not correct?

What angles are present between atoms in a molecule with octahedral geometry?

Using the energy-level diagram for valence orbitals below, determine the bond order of the PO molecule.

Which one of the statements A-D about electron-pair geometry and molecular geometry is not correct?

Oxygen has two common molecular anions: peroxide (O₂²^) and superoxide (O₂^). Use the MO energy level diagram below to identify which one of the following statements is not correct. These molecular orbitals are formed from the 2s and 2p atomic orbitals.

What is the hybridization of the bromine atom in BrF₅?

For which of the following molecules is the electron pair geometry octahedral and the molecular geometry square planar?

Which of the following ions is linear?

Which electron-pair geometry corresponds to a steric number of 5?

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

Which of the following does not represent a  bonding molecular orbital?

Formaldehyde has the formula CH₂O. The carbon atom has a local molecular geometry and hybridization.

A Lewis structure of aspirin without the nonbonding electrons is shown in the figure below. Taking into account the nonbonding electrons, identify the hybridization of the atomic orbitals for the following atoms: O1, O2, and O3. Identify the bond angles around C1, C2, and O3.

In the following reaction, what is the change in geometry of the carbon-containing compound? COCl₂(g)  H₂O(g)  CO₂(g)  2HCl(g)

Both ethane (C₂H₆) and ethylene (C₂H₄) have two carbon atoms. In a valence bond picture of the C-C bonds, hybrid orbitals overlap for ethane and hybrid orbitals overlap for ethylene.

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: The Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acidbase Equilibria: Proton Transfer in Biological Systems

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

The Main Group Elements: Life and the Periodic Table

Transition Metals: Biological and Medical Applications

Filters

Exam 9: Molecular Geometry: Shape Determines Function

Which statement A-D about VSEPR theory is not correct?

Which of the following compounds is the most polar?

Which statement A-D regarding semiconductors is not correct?

What angles are present between atoms in a molecule with octahedral geometry?

Using the energy-level diagram for valence orbitals below, determine the bond order of the PO molecule.

Which one of the statements A-D about electron-pair geometry and molecular geometry is not correct?

Oxygen has two common molecular anions: peroxide (O22) and superoxide (O2). Use the MO energy level diagram below to identify which one of the following statements is not correct. These molecular orbitals are formed from the 2s and 2p atomic orbitals.

What is the hybridization of the bromine atom in BrF5?

For which of the following molecules is the electron pair geometry octahedral and the molecular geometry square planar?

Which of the following ions is linear?

Which electron-pair geometry corresponds to a steric number of 5?

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

Which of the following does not represent a  bonding molecular orbital?

Formaldehyde has the formula CH2O. The carbon atom has a ________ local molecular geometry and ________ hybridization.

A Lewis structure of aspirin without the nonbonding electrons is shown in the figure below. Taking into account the nonbonding electrons, identify the hybridization of the atomic orbitals for the following atoms: O1, O2, and O3. Identify the bond angles around C1, C2, and O3.

In the following reaction, what is the change in geometry of the carbon-containing compound? COCl2(g)  H2O(g)  CO2(g)  2HCl(g)

Both ethane (C2H6) and ethylene (C2H4) have two carbon atoms. In a valence bond picture of the C-C bonds, ________ hybrid orbitals overlap for ethane and ________ hybrid orbitals overlap for ethylene.

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: The Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acidbase Equilibria: Proton Transfer in Biological Systems

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

The Main Group Elements: Life and the Periodic Table

Transition Metals: Biological and Medical Applications

Filters

Oxygen has two common molecular anions: peroxide (O₂²^) and superoxide (O₂^). Use the MO energy level diagram below to identify which one of the following statements is not correct. These molecular orbitals are formed from the 2s and 2p atomic orbitals.

What is the hybridization of the bromine atom in BrF₅?

Formaldehyde has the formula CH₂O. The carbon atom has a local molecular geometry and hybridization.

In the following reaction, what is the change in geometry of the carbon-containing compound? COCl₂(g)  H₂O(g)  CO₂(g)  2HCl(g)

Both ethane (C₂H₆) and ethylene (C₂H₄) have two carbon atoms. In a valence bond picture of the C-C bonds, hybrid orbitals overlap for ethane and hybrid orbitals overlap for ethylene.