Question 1

According to VB theory, a double bond that results from the sharing of four electrons consists of:

Accepted Answer

A)  2 sigma bonds 
B)  one sigma and one pi bond 
C)  one sigma bond 
D)  two pi bonds 
E)  one sigma bond and one coordinate bond 
A)  2 sigma bonds 
B)  one sigma and one pi bond 
C)  one sigma bond 
D)  two pi bonds 
E)  one sigma bond and one coordinate bond B

Question 2

What would be the bond order of the N-C bonds in the benzene-like molecule (C5H5N)?

Accepted Answer

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

Question 3

The "electron-sea" model for bonding in metals, although an oversimplification, offers a reasonable explanation of all of the following metallic properties EXCEPT:

Accepted Answer

A)  ductility 
B)  electrical conductivity 
C)  gaseous diatomic metal molecules 
D)  thermal conductivity 
E)  malleability 
A)  ductility 
B)  electrical conductivity 
C)  gaseous diatomic metal molecules 
D)  thermal conductivity 
E)  malleability C

Question 4

Which of the pairs of molecules below have the same hybridization on the central atom? (The central atom is underlined.)

Accepted Answer

A)  HOCl, ClF3 
B)  H2O, HNO 
C)  HCN, CO2 
D)  BeH2, NH3 
E)  H3COH, CH2O 
A)  HOCl, ClF3 
B)  H2O, HNO 
C)  HCN, CO2 
D)  BeH2, NH3 
E)  H3COH, CH2O

Question 5

Which statement regarding VB theory is INCORRECT?

Accepted Answer

A)  A single bond is a sigma bond. 
B)  A triple bond is two sigma bonds and a pi bond. 
C)  A double bond requires each atom to have an unhybridized p orbital. 
D)  Both atoms in a triple bond have linear geometry. 
E)  sp3 hybridization produces tetrahedral geometry. 
A)  A single bond is a sigma bond. 
B)  A triple bond is two sigma bonds and a pi bond. 
C)  A double bond requires each atom to have an unhybridized p orbital. 
D)  Both atoms in a triple bond have linear geometry. 
E)  sp3 hybridization produces tetrahedral geometry.

Question 6

Which of the following is INCORRECT?

Accepted Answer

A)  Doping is adding a trace of donor or acceptor atoms to pure semiconductor. 
B)  Aluminum would be a donor atom in silicon. 
C)  Extrinsic semiconductors have the band gap controlled by the impurities added. 
D)  Intrinsic semiconductors have a fixed band gap. 
E)  In a p-type semiconductor, the electrical conductivity is due to positive hole migration. 
A)  Doping is adding a trace of donor or acceptor atoms to pure semiconductor. 
B)  Aluminum would be a donor atom in silicon. 
C)  Extrinsic semiconductors have the band gap controlled by the impurities added. 
D)  Intrinsic semiconductors have a fixed band gap. 
E)  In a p-type semiconductor, the electrical conductivity is due to positive hole migration.

Question 7

According to MO theory, which is the INCORRECT statement for N2+?

Accepted Answer

A)  The BO is 2.5. 
B)  There is one unpaired electron. 
C)  The σ2p orbital has one electron in it. 
D)  The molecule is diamagnetic. 
E)  There are 9 electrons in the molecular orbitals. 
A)  The BO is 2.5. 
B)  There is one unpaired electron. 
C)  The σ2p orbital has one electron in it. 
D)  The molecule is diamagnetic. 
E)  There are 9 electrons in the molecular orbitals.

Question 8

Choose the INCORRECT statement about CO2.

Accepted Answer

A)  There are two π bonds. 
B)  There are two σ bonds. 
C)  C has one lone pair. 
D)  The hybridization on C is sp. 
E)  The molecule is linear. 
A)  There are two π bonds. 
B)  There are two σ bonds. 
C)  C has one lone pair. 
D)  The hybridization on C is sp. 
E)  The molecule is linear.

Question 9

All of the following are p-type semiconductors EXCEPT:

Accepted Answer

A)  As in Si. 
B)  Al in Si. 
C)  B in Ge. 
D)  In in Se. 
A)  As in Si. 
B)  Al in Si. 
C)  B in Ge. 
D)  In in Se.

Question 10

The structure of aspirin is given below.   What is the O-C-C bond angle, "x", in aspirin?

Accepted Answer

A)  ~120° 
B)  ~109° 
C)  ~90° 
D)  ~180° 
A)  ~120° 
B)  ~109° 
C)  ~90° 
D)  ~180°

Question 11

For BeCl2, the dipole moment of the molecule, hybridization on the central atom, and number of lone pairs on the central atom are:

Accepted Answer

A)  toward Be, sp2, none 
B)  away from Be, sp2, one 
C)  none, sp, none 
D)  toward Be, sp, one 
E)  none, sp3, two 
A)  toward Be, sp2, none 
B)  away from Be, sp2, one 
C)  none, sp, none 
D)  toward Be, sp, one 
E)  none, sp3, two

Question 12

According to MO theory, which is the INCORRECT statement for C2-?

Accepted Answer

A)  The BO is 2.5. 
B)  There is one unpaired electron. 
C)  The σ2p orbital has two electrons. 
D)  The molecule is paramagnetic. 
E)  There are 9 electrons in the molecular orbitals. 
A)  The BO is 2.5. 
B)  There is one unpaired electron. 
C)  The σ2p orbital has two electrons. 
D)  The molecule is paramagnetic. 
E)  There are 9 electrons in the molecular orbitals.

Question 13

The extra stability that a molecule gains due to electron delocalizations (the electrons being free to move throughout large parts of the molecule) is called:

Accepted Answer

A)  ionization energy 
B)  lattice energy 
C)  covalent strength 
D)  resonance energy 
E)  bond energy 
A)  ionization energy 
B)  lattice energy 
C)  covalent strength 
D)  resonance energy 
E)  bond energy

Question 14

Three of the molecular shapes which a sp3d hybridized molecule can have are:

Accepted Answer

A)  triangular, trigonal bipyramid, linear 
B)  linear, square planar, T-shaped 
C)  irregular tetrahedron, T-shaped, bent 
D)  T-shaped, linear, trigonal bipyramid 
E)  linear, tetragonal pyramid, octahedral 
A)  triangular, trigonal bipyramid, linear 
B)  linear, square planar, T-shaped 
C)  irregular tetrahedron, T-shaped, bent 
D)  T-shaped, linear, trigonal bipyramid 
E)  linear, tetragonal pyramid, octahedral

Question 15

How would replacing one of benzene's C atoms and the H atom attached to it with an N atom (C5H5N) affect the delocalized electrons?

Accepted Answer

A)  The molecule would not be stable. 
B)  The N can have delocalized electrons like C. 
C)  Only the five C atoms would be included in the delocalized electrons. 
D)  There would be no delocalized electrons but a double bond between the N and a C. 
E)  There would be no delocalized electrons but a double bond between the N and the C on each side of the N. 
A)  The molecule would not be stable. 
B)  The N can have delocalized electrons like C. 
C)  Only the five C atoms would be included in the delocalized electrons. 
D)  There would be no delocalized electrons but a double bond between the N and a C. 
E)  There would be no delocalized electrons but a double bond between the N and the C on each side of the N.

Question 16

Resonance structures and delocalized orbitals are different ways to describe the same bonding.

Accepted Answer

A) True 
 B)False

Question 17

Which of the following does NOT involve any delocalized π bonds?

Accepted Answer

A)  acetate ion 
B)  carbonate ion 
C)  nitric acid 
D)  nitrous acid 
E)  ozone 
A)  acetate ion 
B)  carbonate ion 
C)  nitric acid 
D)  nitrous acid 
E)  ozone

Question 18

A double bond is two sigma bonds.

Accepted Answer

A) True 
 B)False

Question 19

In a semiconductor, the energy gap between the valence band and the conduction band is large.

Accepted Answer

A) True 
 B)False

Question 20

Which statement is INCORRECT?

Accepted Answer

A)  The bond length is the internuclear distance. 
B)  The covalent bond is a region of high electron charge density between two atoms. 
C)  Hybrid orbitals are combinations of atomic orbitals. 
D)  There are the same number of hybrid orbitals produced as the number of atomic orbitals combined. 
E)  An sp hybridization produces a tetrahedral molecule. 
A)  The bond length is the internuclear distance. 
B)  The covalent bond is a region of high electron charge density between two atoms. 
C)  Hybrid orbitals are combinations of atomic orbitals. 
D)  There are the same number of hybrid orbitals produced as the number of atomic orbitals combined. 
E)  An sp hybridization produces a tetrahedral molecule.

Exam 11: Chemical Bonding II: Additional Aspects

According to VB theory, a double bond that results from the sharing of four electrons consists of:

What would be the bond order of the N-C bonds in the benzene-like molecule (C5H5N)?

The "electron-sea" model for bonding in metals, although an oversimplification, offers a reasonable explanation of all of the following metallic properties EXCEPT:

Which of the pairs of molecules below have the same hybridization on the central atom? (The central atom is underlined.)

Which statement regarding VB theory is INCORRECT?

Which of the following is INCORRECT?

According to MO theory, which is the INCORRECT statement for N2+?

Choose the INCORRECT statement about CO2.

All of the following are p-type semiconductors EXCEPT:

The structure of aspirin is given below. What is the O-C-C bond angle, "x", in aspirin?

For BeCl2, the dipole moment of the molecule, hybridization on the central atom, and number of lone pairs on the central atom are:

According to MO theory, which is the INCORRECT statement for C2-?

The extra stability that a molecule gains due to electron delocalizations (the electrons being free to move throughout large parts of the molecule) is called:

Three of the molecular shapes which a sp3d hybridized molecule can have are:

How would replacing one of benzene's C atoms and the H atom attached to it with an N atom (C5H5N) affect the delocalized electrons?

Resonance structures and delocalized orbitals are different ways to describe the same bonding.

Which of the following does NOT involve any delocalized π bonds?

A double bond is two sigma bonds.

In a semiconductor, the energy gap between the valence band and the conduction band is large.

Which statement is INCORRECT?

Matter - Its Properties and Measurement

Atoms and the Atomic Theory

Chemical Compounds

Chemical Reactions

Introduction to Reactions in Aqueous Solutions

Gases

Thermochemistry

Electrons in Atoms

The Periodic Table and Some Atomic Properties

Chemical Bonding I: Basic Concepts

Intermolecular Forces: Liquids and Solids

Solutions and Their Physical Properties

Chemical Kinetics

Principles of Chemical Equilibrium

Acids and Bases

Additional Aspects of Acid-Base Equilibria

Solubility and Complex-Ion Equilibria

Spontaneous Change: Entropy and Free Energy

Electrochemistry

Main Group Elements I: Groups 1, 2, 13, and 14

Main Group Elements II: Groups 18, 17, 16, 15, and Hydrogen

The Transition Elements

Complex Ions and Coordination Compounds

Nuclear Chemistry 1-41

Structures of Organic Compounds

Reactions of Organic Compounds

Chemistry of the Living State

Filters

What would be the bond order of the N-C bonds in the benzene-like molecule (C₅H₅N)?

According to MO theory, which is the INCORRECT statement for N²⁺?

Choose the INCORRECT statement about CO₂.

For BeCl₂, the dipole moment of the molecule, hybridization on the central atom, and number of lone pairs on the central atom are:

How would replacing one of benzene's C atoms and the H atom attached to it with an N atom (C₅H₅N) affect the delocalized electrons?