Question 1

Explain what is meant by "dipole moment", and give an example of a molecule which has polar bonds but which does not itself have a dipole moment.

Accepted Answer

A dipole moment arises in a molecule whe

Question 2

According to VSEPR theory, a molecule with the general formula AX4 will have a ______ molecular shape.

Accepted Answer

A)  bent 
B)  trigonal planar 
C)  trigonal pyramidal 
D)  square planar 
E)  tetrahedral 
A)  bent 
B)  trigonal planar 
C)  trigonal pyramidal 
D)  square planar 
E)  tetrahedral

Question 3

What is the molecular shape of ClCN as predicted by the VSEPR theory? (Carbon is the central atom.)

Accepted Answer

A)  linear 
B)  bent 
C)  angular 
D)  trigonal 
E)  None of these choices is correct. 
A)  linear 
B)  bent 
C)  angular 
D)  trigonal 
E)  None of these choices is correct.

Question 4

Considering all the bonds in a molecule with trigonal bipyramidal geometry, what are the bond angles present?

Accepted Answer

A)  120 $\degree$ only 
B)  90 $\degree$ only 
C)  180 $\degree$ only 
D)  60 $\degree$ and 90 $\degree$only 
E)  90 $\degree$, 120 $\degree$and 180 $\degree$ 
A)  120 $\degree$ only 
B)  90 $\degree$ only 
C)  180 $\degree$ only 
D)  60 $\degree$ and 90 $\degree$only 
E)  90 $\degree$, 120 $\degree$and 180 $\degree$

Question 5

Boron never achieves an octet in any of its compounds.

Accepted Answer

A) True 
 B)False

Question 6

How many faces and how many vertexes (corners), respectively, are there in a trigonal bipyramid?

Accepted Answer

A)  4 and 4 
B)  5 and 5 
C)  5 and 6 
D)  6 and 5 
E)  6 and 8 
A)  4 and 4 
B)  5 and 5 
C)  5 and 6 
D)  6 and 5 
E)  6 and 8

Question 7

The best Lewis structure for sulfuric acid has zero formal charges, sulfur as the central atom, and no bonds between S and H. How many single and double bonds, respectively, are there in this Lewis structure?

Accepted Answer

A)  2 single, 4 double 
B)  4 single, 2 double 
C)  4 single, no double 
D)  6 single, no double 
E)  5 single, 1 double 
A)  2 single, 4 double 
B)  4 single, 2 double 
C)  4 single, no double 
D)  6 single, no double 
E)  5 single, 1 double

Question 8

In the following Lewis structure for phosphate, phosphorus has a formal charge of ____ and an oxidation number of ____.

Accepted Answer

A)  0, -3 
B)  0, 5 
C)  5, -3 
D)  5, 5 
E)  3, 5 
A)  0, -3 
B)  0, 5 
C)  5, -3 
D)  5, 5 
E)  3, 5

Question 9

What is the molecular shape of ClF4¯ as predicted by the VSEPR theory?

Accepted Answer

A)  square pyramidal 
B)  square planar 
C)  see-saw 
D)  octahedral 
E)  tetrahedral 
A)  square pyramidal 
B)  square planar 
C)  see-saw 
D)  octahedral 
E)  tetrahedral

Question 10

List all possible molecular geometries (shapes) for a nonpolar molecule with the formula AX4.

Accepted Answer

A)  tetrahedral 
B)  seesaw 
C)  square planar 
D)  either tetrahedral or square planar 
E)  All of these choices are possible. 
A)  tetrahedral 
B)  seesaw 
C)  square planar 
D)  either tetrahedral or square planar 
E)  All of these choices are possible.

Question 11

In order for a non-cyclic triatomic molecule to be bent, VSEPR theory requires that there must be two lone pairs on the central atom.

Accepted Answer

A) True 
 B)False

Question 12

Thionyl chloride is used as an oxidizing and chlorinating agent in organic chemistry. Select the best Lewis structure for SOCl2.

Accepted Answer

A)    
B)    
C)    
D)    
E)  None of these structures is suitable for SOCl2. 
A)    
B)    
C)    
D)    
E)  None of these structures is suitable for SOCl2.

Question 13

What is the molecular shape of SiF62¯ as predicted by the VSEPR theory?

Accepted Answer

A)  trigonal bipyramidal 
B)  hexagonal 
C)  tetrahedral 
D)  see-saw 
E)  octahedral 
A)  trigonal bipyramidal 
B)  hexagonal 
C)  tetrahedral 
D)  see-saw 
E)  octahedral

Question 14

In a Lewis structure for a molecule or ion, the sum of the formal charges on the atoms is equal to the charge on the molecule or ion.

Accepted Answer

A) True 
 B)False

Question 15

Which one of the following molecules does not have a dipole moment?

Accepted Answer

A)  CS2 
B)  H2S 
C)  CH2Cl2 
D)  PH3 
E)  CH2O 
A)  CS2 
B)  H2S 
C)  CH2Cl2 
D)  PH3 
E)  CH2O

Question 16

Draw Lewis structures, showing all valence electrons, for the following species:
A) S2¯
b. CO
C) SO2
d. CH3OH

Accepted Answer

Question 17

Hydrazine, N2H4, is a good reducing agent that has been used as a component in rocket fuels. Select its Lewis structure.

Accepted Answer

A)    
B)    
C)    
D)    
E)  None of these choices is correct. 
A)    
B)    
C)    
D)    
E)  None of these choices is correct.

Question 18

According to VSEPR theory, a molecule with the general formula AX3 will have a ______ molecular shape.

Accepted Answer

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

Question 19

Phosphoryl iodide is used in the preparation of organophosphorus derivatives and phosphate esters. Select the Lewis structure for POI3 which minimizes formal charges.

Accepted Answer

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

Question 20

Draw Lewis structures, showing all valence electrons, for:
A) N
B) Br¯
c. O2
d. SO42¯

Accepted Answer

Exam 10: The Shapes of Molecules

Explain what is meant by "dipole moment", and give an example of a molecule which has polar bonds but which does not itself have a dipole moment.

According to VSEPR theory, a molecule with the general formula AX4 will have a ______ molecular shape.

What is the molecular shape of ClCN as predicted by the VSEPR theory? (Carbon is the central atom.)

Considering all the bonds in a molecule with trigonal bipyramidal geometry, what are the bond angles present?

Boron never achieves an octet in any of its compounds.

How many faces and how many vertexes (corners), respectively, are there in a trigonal bipyramid?

The best Lewis structure for sulfuric acid has zero formal charges, sulfur as the central atom, and no bonds between S and H. How many single and double bonds, respectively, are there in this Lewis structure?

In the following Lewis structure for phosphate, phosphorus has a formal charge of ____ and an oxidation number of ____.

What is the molecular shape of ClF4¯ as predicted by the VSEPR theory?

List all possible molecular geometries (shapes) for a nonpolar molecule with the formula AX4.

In order for a non-cyclic triatomic molecule to be bent, VSEPR theory requires that there must be two lone pairs on the central atom.

Thionyl chloride is used as an oxidizing and chlorinating agent in organic chemistry. Select the best Lewis structure for SOCl2.

What is the molecular shape of SiF62¯ as predicted by the VSEPR theory?

In a Lewis structure for a molecule or ion, the sum of the formal charges on the atoms is equal to the charge on the molecule or ion.

Which one of the following molecules does not have a dipole moment?

Draw Lewis structures, showing all valence electrons, for the following species: A) S2¯ b. CO C) SO2 d. CH3OH

Hydrazine, N2H4, is a good reducing agent that has been used as a component in rocket fuels. Select its Lewis structure.

According to VSEPR theory, a molecule with the general formula AX3 will have a ______ molecular shape.

Phosphoryl iodide is used in the preparation of organophosphorus derivatives and phosphate esters. Select the Lewis structure for POI3 which minimizes formal charges.

Draw Lewis structures, showing all valence electrons, for: A) N B) Br¯ c. O2 d. SO42¯

Keys to the Study of Chemistry

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

Theories of Covalent Bonding

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 the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

According to VSEPR theory, a molecule with the general formula AX₄ will have a ______ molecular shape.

In the following Lewis structure for phosphate, phosphorus has a formal charge of and an oxidation number of .

What is the molecular shape of ClF₄^¯ as predicted by the VSEPR theory?

List all possible molecular geometries (shapes) for a nonpolar molecule with the formula AX₄.

Thionyl chloride is used as an oxidizing and chlorinating agent in organic chemistry. Select the best Lewis structure for SOCl₂.

What is the molecular shape of SiF₆^2¯ as predicted by the VSEPR theory?

Draw Lewis structures, showing all valence electrons, for the following species: A) S^2¯b. CO C) SO₂d. CH₃OH

Hydrazine, N₂H₄, is a good reducing agent that has been used as a component in rocket fuels. Select its Lewis structure.

According to VSEPR theory, a molecule with the general formula AX₃ will have a ______ molecular shape.

Phosphoryl iodide is used in the preparation of organophosphorus derivatives and phosphate esters. Select the Lewis structure for POI₃ which minimizes formal charges.

Draw Lewis structures, showing all valence electrons, for: A) N B) Br^¯c. O₂d. SO₄^2¯