Question 1

Are the π-bonds in CH3CO2- delocalized or localized?

Accepted Answer

delocalized

Question 2

What is the geometry around the central atom in the following molecular model of NO2-?

Accepted Answer

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

Question 3

Identify the set of hybrid orbitals shown below.

Accepted Answer

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

Question 4

Which drawing represents the lowest energy unoccupied molecular orbital in the N2 molecule in its ground state?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 5

The hybrid orbital used by nitrogen to overlap with the 1s orbital of hydrogen in CH3NH2 is ________.

Accepted Answer

Question 6

A molecular model of BCl3 is shown below.Based on the best Lewis electron-dot structure for BCl3 and formal charge considerations,what is the predicted B-Cl bond order for each B-Cl bond?

Accepted Answer

A) 1 
B) 1)33 
C) 1)5 
D) 2 
A) 1 
B) 1)33 
C) 1)5 
D) 2

Question 7

Which drawing represents a π* antibonding molecular orbital for a homonuclear diatomic molecule?

Accepted Answer

A)    
B)    
C)    
D)    
A)    
B)    
C)    
D)

Question 8

Which is the longest bond?

Accepted Answer

A) N-N 
B) N N 
C) N=N 
D) All three bond lengths should be about the same. 
A) N-N 
B) N N 
C) N=N 
D) All three bond lengths should be about the same.

Question 9

Which of the following is not true?

Accepted Answer

A) The sp3 hybrid orbitals are degenerate. 
B) An sp3 hybrid orbital may hold a lone pair of electrons. 
C) An sp3 hybrid orbital may form a sigma bond by overlap with an orbital on another atom. 
D) An sp3 hybrid orbital may form a pi bond by overlap with an orbital on another atom. 
A) The sp3 hybrid orbitals are degenerate. 
B) An sp3 hybrid orbital may hold a lone pair of electrons. 
C) An sp3 hybrid orbital may form a sigma bond by overlap with an orbital on another atom. 
D) An sp3 hybrid orbital may form a pi bond by overlap with an orbital on another atom.

Question 10

Which of the following are allowed resonance forms of NCS-?

Accepted Answer

A) only I 
B) only II 
C) only III 
D) I and III 
A) only I 
B) only II 
C) only III 
D) I and III

Question 11

When an electron is added to the lowest unoccupied molecular orbital of N2,the electron is added to a(n)________ (antibonding,bonding)molecular orbital and the N-N bond order will ________ (decrease,increase).

Accepted Answer

antibondin

Question 12

Among the compounds H3C-CH3,H2C=CH2,and HC=CH,the compound with the strongest carbon-carbon bond is ________,and the compound with the longest carbon-carbon bond is ________.

Accepted Answer

Question 13

Which of the following should be nonplanar?

Accepted Answer

A) only I 
B) only II 
C) only III 
D) I and III 
A) only I 
B) only II 
C) only III 
D) I and III

Question 14

A single sp3 hybrid orbital has

Accepted Answer

A) one lobe. 
B) two lobes of equal size. 
C) two lobes of unequal size. 
D) four lobes of equal size. 
A) one lobe. 
B) two lobes of equal size. 
C) two lobes of unequal size. 
D) four lobes of equal size.

Question 15

What is the geometry around the central atom in the following molecular model of I3-?

Accepted Answer

A) trigonal bipyramidal 
B) seesaw 
C) T-shaped 
D) linear 
A) trigonal bipyramidal 
B) seesaw 
C) T-shaped 
D) linear

Question 16

In general,at room temperature

Accepted Answer

A) ionic compounds are all solids and covalent compounds are all gases. 
B) ionic compounds are all solids,but covalent compounds may be solids,liquids,or gases. 
C) ionic compounds are all solids,and covalent compounds are liquids or gases. 
D) covalent compounds are all gases,but ionic compounds may be solids,liquids,or gases. 
A) ionic compounds are all solids and covalent compounds are all gases. 
B) ionic compounds are all solids,but covalent compounds may be solids,liquids,or gases. 
C) ionic compounds are all solids,and covalent compounds are liquids or gases. 
D) covalent compounds are all gases,but ionic compounds may be solids,liquids,or gases.

Question 17

What is the bond angle in the following molecular model of H2S?

Accepted Answer

A) less than 109.5° 
B) 109.5° 
C) less than 120° but greater than 109.5° 
D) 120° 
A) less than 109.5° 
B) 109.5° 
C) less than 120° but greater than 109.5° 
D) 120°

Question 18

The Lewis electron-dot structure of H2CO has ________ nonbonding electron pairs,________ bonding electron pairs,and a carbon-oxygen bond order of ________.

Accepted Answer

Question 19

Which statement concerning any homonuclear diatomic molecule and its 1- ion must be true?

Accepted Answer

A) X2 must be more stable than X2-. 
B) X2 must be less stable than X2-. 
C) X2- must be paramagnetic and X2 must be diamagnetic. 
D) X2- must be paramagnetic and X2 may be paramagnetic or diamagnetic. 
A) X2 must be more stable than X2-. 
B) X2 must be less stable than X2-. 
C) X2- must be paramagnetic and X2 must be diamagnetic. 
D) X2- must be paramagnetic and X2 may be paramagnetic or diamagnetic.

Question 20

Arrange the following in order of increasing ionic character: Al2S3,MgS,Na2S,P4S3,S8.

Accepted Answer

A) MgS,Na2S,Al2S3,P4S3,S8 
B) Na2S,MgS,Al2S3,P4S3,S8 
C) S8,P4S3,Al2S3,MgS,Na2S 
D) S8,P4S3,Al2S3,Na2S,MgS 
A) MgS,Na2S,Al2S3,P4S3,S8 
B) Na2S,MgS,Al2S3,P4S3,S8 
C) S8,P4S3,Al2S3,MgS,Na2S 
D) S8,P4S3,Al2S3,Na2S,MgS

Exam 7: Covalent Bonds and Molecular Structure

Are the π-bonds in CH3CO2- delocalized or localized?

What is the geometry around the central atom in the following molecular model of NO2-?

Identify the set of hybrid orbitals shown below.

Which drawing represents the lowest energy unoccupied molecular orbital in the N2 molecule in its ground state?

The hybrid orbital used by nitrogen to overlap with the 1s orbital of hydrogen in CH3NH2 is ________.

A molecular model of BCl3 is shown below.Based on the best Lewis electron-dot structure for BCl3 and formal charge considerations,what is the predicted B-Cl bond order for each B-Cl bond?

Which drawing represents a π* antibonding molecular orbital for a homonuclear diatomic molecule?

Which is the longest bond?

Which of the following is not true?

Which of the following are allowed resonance forms of NCS-?

When an electron is added to the lowest unoccupied molecular orbital of N2,the electron is added to a(n)________ (antibonding,bonding)molecular orbital and the N-N bond order will ________ (decrease,increase).

Among the compounds H3C-CH3,H2C=CH2,and HC=CH,the compound with the strongest carbon-carbon bond is ________,and the compound with the longest carbon-carbon bond is ________.

Which of the following should be nonplanar?

A single sp3 hybrid orbital has

What is the geometry around the central atom in the following molecular model of I3-?

In general,at room temperature

What is the bond angle in the following molecular model of H2S?

The Lewis electron-dot structure of H2CO has ________ nonbonding electron pairs,________ bonding electron pairs,and a carbon-oxygen bond order of ________.

Which statement concerning any homonuclear diatomic molecule and its 1- ion must be true?

Arrange the following in order of increasing ionic character: Al2S3,MgS,Na2S,P4S3,S8.

Chemistry: Matter and Measurement

Atoms, molecules, and Ions

Formulas, equations, and Moles

Reactions in Aqueous Solutions

Periodicity and the Atomic Structure of Atoms

Ionic Bonds and Some Main-Group Chemistry

Thermochemistry: Chemical Energy

Gases: Their Properties and Behavior

Liquids,solids,and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Electrochemistry

Hydrogen, oxygen, and Water

The Main-Group Elements

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

Nuclear Chemistry

Organic and Biological Chemistry

Filters

Are the π-bonds in CH₃CO₂^- delocalized or localized?

What is the geometry around the central atom in the following molecular model of NO₂^-?

Which drawing represents the lowest energy unoccupied molecular orbital in the N₂ molecule in its ground state?

The hybrid orbital used by nitrogen to overlap with the 1s orbital of hydrogen in CH₃NH₂ is ________.

A molecular model of BCl₃ is shown below.Based on the best Lewis electron-dot structure for BCl₃ and formal charge considerations,what is the predicted B-Cl bond order for each B-Cl bond?

Which drawing represents a π^* antibonding molecular orbital for a homonuclear diatomic molecule?

Which of the following are allowed resonance forms of NCS^-?

When an electron is added to the lowest unoccupied molecular orbital of N₂,the electron is added to a(n) (antibonding,bonding)molecular orbital and the N-N bond order will (decrease,increase).

Among the compounds H₃C-CH₃,H₂C=CH₂,and HC=CH,the compound with the strongest carbon-carbon bond is ,and the compound with the longest carbon-carbon bond is .

A single sp³ hybrid orbital has

What is the geometry around the central atom in the following molecular model of I₃^-?

What is the bond angle in the following molecular model of H₂S?

The Lewis electron-dot structure of H₂CO has nonbonding electron pairs, bonding electron pairs,and a carbon-oxygen bond order of .

Arrange the following in order of increasing ionic character: Al₂S₃,MgS,Na₂S,P₄S₃,S₈.