Question 1

When resonance occurs, the bond lengths in a molecule fluctuate rapidly.

Accepted Answer

A) True 
 B)False  False

Question 2

What is the molecular shape of N2O as predicted by the VSEPR theory?

Accepted Answer

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

Question 3

A) Draw and name three molecular shapes for molecules having the VSEPR formulas AX3, AX3E and AX3E2, respectively.
B) If the three X groups in the above formulas are identical, which of the three shapes would result in a molecule with a dipole moment?

Accepted Answer

a. The three structures and their molecular shapes are shown below.   b. The trigonal pyramidal and T-shaped molecules will have dipole moments.

Question 4

In formaldehyde, CH2O, both the formal charge and the oxidation number of carbon are zero.

Accepted Answer

A) True 
 B)False

Question 5

What is the molecular shape of the thiocyanate anion, SCN¯, 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 6

In the nitrate ion (NO3¯), nitrogen and oxygen are held together by

Accepted Answer

A)  ionic interactions. 
B)  covalent bonds. 
C)  dative bonds. 
D)  electronegativity. 
E)  network bonds. 
A)  ionic interactions. 
B)  covalent bonds. 
C)  dative bonds. 
D)  electronegativity. 
E)  network bonds.

Question 7

Predict the ideal bond angles around nitrogen in N2F2 using the molecular shape given by the VSEPR theory. (The two N atoms are the central atoms.)

Accepted Answer

A)  90 $\degree$ 
B)  109 $\degree$ 
C)  120 $\degree$ 
D)  180 $\degree$ 
E)  between 120 and 180 $\degree$ 
A)  90 $\degree$ 
B)  109 $\degree$ 
C)  120 $\degree$ 
D)  180 $\degree$ 
E)  between 120 and 180 $\degree$

Question 8

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

Accepted Answer

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

Question 9

What is the molecular shape of XeO2F2 as predicted by the VSEPR theory?

Accepted Answer

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

Question 10

In which of the following does the nitrogen atom have a formal charge of -1?

Accepted Answer

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

Question 11

In which one of the following is the best Lewis structure a resonance structure?

Accepted Answer

A)  CO2 (C = central atom) 
B)  ClO3¯ (Cl = central atom) 
C)  COCl2 (C = central atom) 
D)  NO2+ (N = central atom) 
E)  HCN (C = central atom) 
A)  CO2 (C = central atom) 
B)  ClO3¯ (Cl = central atom) 
C)  COCl2 (C = central atom) 
D)  NO2+ (N = central atom) 
E)  HCN (C = central atom)

Question 12

According to VSEPR theory, a molecule with the general formula AX5E will have a ______ molecular shape.

Accepted Answer

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

Question 13

According to VSEPR theory, a molecule with the general formula AX3E2 will have a _____ molecular shape.

Accepted Answer

A)  trigonal pyramidal 
B)  trigonal bipyramidal 
C)  trigonal planar 
D)  T-shaped 
E)  see-saw 
A)  trigonal pyramidal 
B)  trigonal bipyramidal 
C)  trigonal planar 
D)  T-shaped 
E)  see-saw

Question 14

In the COCl2 molecule, carbon is the central atom. Based on the best Lewis structure for COCl2, what is the formal charge on carbon?

Accepted Answer

A)  0 
B)  +1 
C)  -1 
D)  +2 
E)  -2 
A)  0 
B)  +1 
C)  -1 
D)  +2 
E)  -2

Question 15

Which one of the following Lewis structures is definitely incorrect?

Accepted Answer

A)  NO   
B)  HCN   
C)  NO2¯   
D)  SO32¯   
E)  PCl5   
A)  NO   
B)  HCN   
C)  NO2¯   
D)  SO32¯   
E)  PCl5

Question 16

According to VSEPR theory, a molecule with the general formula AX4E will have a _____ molecular shape.

Accepted Answer

A)  bent 
B)  see-saw 
C)  trigonal planar 
D)  T-shaped 
E)  square planar 
A)  bent 
B)  see-saw 
C)  trigonal planar 
D)  T-shaped 
E)  square planar

Question 17

What is the molecular shape of NO2¯ as predicted by the VSEPR theory?

Accepted Answer

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

Question 18

The formal charge on Cl in the structure shown for the perchlorate ion is:

Accepted Answer

A)  -2 
B)  -1 
C)  0 
D)  +1 
E)  +2 
A)  -2 
B)  -1 
C)  0 
D)  +1 
E)  +2

Question 19

The Lewis structure of NO2 violates the octet rule.

Accepted Answer

A) True 
 B)False

Question 20

What is the shape of the PF3 molecule? Explain your answer, using VSEPR theory.

Accepted Answer

The Lewis structure has a lone pair on t

Exam 10: The Shapes of Molecules

When resonance occurs, the bond lengths in a molecule fluctuate rapidly.

What is the molecular shape of N2O as predicted by the VSEPR theory?

A) Draw and name three molecular shapes for molecules having the VSEPR formulas AX3, AX3E and AX3E2, respectively. B) If the three X groups in the above formulas are identical, which of the three shapes would result in a molecule with a dipole moment?

In formaldehyde, CH2O, both the formal charge and the oxidation number of carbon are zero.

What is the molecular shape of the thiocyanate anion, SCN¯, as predicted by the VSEPR theory? (Carbon is the central atom.)

In the nitrate ion (NO3¯), nitrogen and oxygen are held together by

Predict the ideal bond angles around nitrogen in N2F2 using the molecular shape given by the VSEPR theory. (The two N atoms are the central atoms.)

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

What is the molecular shape of XeO2F2 as predicted by the VSEPR theory?

In which of the following does the nitrogen atom have a formal charge of -1?

In which one of the following is the best Lewis structure a resonance structure?

According to VSEPR theory, a molecule with the general formula AX5E will have a ______ molecular shape.

According to VSEPR theory, a molecule with the general formula AX3E2 will have a _____ molecular shape.

In the COCl2 molecule, carbon is the central atom. Based on the best Lewis structure for COCl2, what is the formal charge on carbon?

Which one of the following Lewis structures is definitely incorrect?

According to VSEPR theory, a molecule with the general formula AX4E will have a _____ molecular shape.

What is the molecular shape of NO2¯ as predicted by the VSEPR theory?

The formal charge on Cl in the structure shown for the perchlorate ion is:

The Lewis structure of NO2 violates the octet rule.

What is the shape of the PF3 molecule? Explain your answer, using VSEPR theory.

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

What is the molecular shape of N₂O as predicted by the VSEPR theory?

A) Draw and name three molecular shapes for molecules having the VSEPR formulas AX₃, AX₃E and AX₃E₂, respectively. B) If the three X groups in the above formulas are identical, which of the three shapes would result in a molecule with a dipole moment?

In formaldehyde, CH₂O, both the formal charge and the oxidation number of carbon are zero.

What is the molecular shape of the thiocyanate anion, SCN^¯, as predicted by the VSEPR theory? (Carbon is the central atom.)

In the nitrate ion (NO₃^¯), nitrogen and oxygen are held together by

Predict the ideal bond angles around nitrogen in N₂F₂ using the molecular shape given by the VSEPR theory. (The two N atoms are the central atoms.)

What is the molecular shape of XeO₂F₂ as predicted by the VSEPR theory?

According to VSEPR theory, a molecule with the general formula AX₅E will have a ______ molecular shape.

According to VSEPR theory, a molecule with the general formula AX₃E₂ will have a _____ molecular shape.

In the COCl₂ molecule, carbon is the central atom. Based on the best Lewis structure for COCl₂, what is the formal charge on carbon?

According to VSEPR theory, a molecule with the general formula AX₄E will have a _____ molecular shape.

What is the molecular shape of NO₂^¯ as predicted by the VSEPR theory?

The Lewis structure of NO₂ violates the octet rule.

What is the shape of the PF₃ molecule? Explain your answer, using VSEPR theory.