Deck 6: Molecular Shape

Question 1

How many lone pairs of electrons need to be added to complete this Lewis structure?

A)5
B)8
C)6
D)1
E)16

Answer 1

8

Question 2

In which one of the following species is the central atom (the first atom in the formula) likely to violate the octet rule?

A)BF₄⁻
B)XeO₃
C)SiCl₄
D)NH₃
E)CH₂Cl₂

Answer 2

XeO₃

Question 3

What does the abbreviation VSEPR stand for?

A)Very Specific Electron and Proton Repair
B)Variable Selective of Electron and Protons
C)Valence Shell for Every Proton
D)Very Selective Electron Pair theory
E)Valence-Shell Electron-Pair Repulsion

Answer 3

Valence-Shell Electron-Pair Repulsion

Question 4

The number of resonance structures for the nitrate ion that satisfy the octet rule is

A)1.
B)2.
C)3.
D)4.
E)none of these

Question 5

How many lone pairs of electrons need to be added to complete this Lewis structure?

A)5
B)10
C)0
D)1
E)6

Question 6

Select the correct Lewis structure for NOCl, a reactive material used as an ionizing solvent.

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

Question 7

According to the VSEPR model, the predicted molecular geometry of the SO₃ molecule is

A)pyramidal.
B)tetrahedral.
C)trigonal planar.
D)seesaw.
E)square planar.

Question 8

Select the correct Lewis structure for nitrogen trifluoride, NF₃.

A)
B)
C)
D)
E)

Question 9

What is the predicted molecular geometry of the CH₄ molecule according to the VSEPR model?

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

Question 10

How many total resonance structures can be drawn for the sulfate ion, SO₄²⁻?

A)2
B)3
C)4
D)5
E)6

Question 11

Which of the following is required for the determination of the VSEPR model and the molecular shape?

A)Atomic mass
B)Number of protons
C)Oxidation number
D)Lewis structure
E)None of the answers is correct.

Question 12

The total number of lone pairs in NCl₃ is

A)6.
B)8.
C)9.
D)10.
E)13.

Question 13

The Lewis structure for CS₂ is:

A)
B)
C)
D)

Question 14

The total number of bonding electrons in a molecule of formaldehyde (H₂CO) is

A)3.
B)4.
C)6.
D)8.
E)18.

Question 15

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

A)SO₃
B)BF₃
C)I₃⁻
D)SCO (C = central atom)
E)SO₃²⁻

Question 16

The number of resonance structures for the sulfur dioxide molecule that satisfy the octet rule is

A)1.
B)2.
C)3.
D)4.
E)none of these

Question 17

The Lewis structure for a chlorate ion, ClO₃^-, should show ____ single bond(s), ____ double bond(s), and ____ lone pair(s).

A)2, 1, 10
B)3, 0, 9
C)2, 1, 8
D)3, 0, 10
E)2, 1, 9

Question 18

What is wrong with this Lewis structure?

A)There are too many electrons.
B)There are too few electrons.
C)The O atom does not have an octet.
D)The C atom does not have an octet.
E)There is nothing wrong with this Lewis structure.

Question 19

Which of these choices is the best Lewis structure for ozone, O₃?

A)
B)
C)
D)
E)

Question 20

Which pair of Lewis structures is not a pair of resonance structures?

A)
B)
C)
D)All of these pairs are resonance structures of the same species.
E)None of these pairs is resonance structures of the same species.

Question 21

Using the VSEPR model, predict the molecular geometry around the central atom in SO₃²⁻.

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

Question 22

What is the molecular geometry of HOF as predicted by the VSEPR model?

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

Question 23

According to the VSEPR model, the predicted molecular geometry of SiCl₄ is

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

Question 24

Using the VSEPR model, predict the molecular geometry around the central atom in PO₄³⁻.

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

Question 25

What is the number of lone electron pairs on the central atom of a molecule having a linear molecular geometry, such as ClF₂⁻?

A)1
B)2
C)3
D)0
E)4

Question 26

What is the molecular geometry of NO₂⁻ as predicted by the VSEPR model?

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

Question 27

What is the molecular geometry of BeH₂ as predicted by the VSEPR model?

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

Question 28

What is the molecular geometry of N₂O as predicted by the VSEPR model?

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

Question 29

According to the VSEPR model, a molecule with the general formula AB₂ with two lone pairs on the central atom will have a _____ molecular geometry.

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

Question 30

According to the VSEPR model, which molecule is predicted to be linear?

A)H₂S
B)HCN
C)BF₃
D)H₂CO
E)SO₃

Question 31

According to the VSEPR model, the predicted molecular geometry of ammonia, NH₃, is

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

Question 32

What is the number of lone electron pairs on the central atom of a molecule having a trigonal pyramidal molecular geometry, such as NH₃?

A)1
B)2
C)3
D)0
E)4

Question 33

Using the VSEPR model, what is the predicted molecular geometry of the PCl₃ molecule?

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

Question 34

What is the number of lone electron pairs on the central atom of a molecule having a linear molecular geometry, such as CO₂?

A)1
B)2
C)3
D)0
E)4

Question 35

According to the VSEPR model, a molecule with the general formula AB₃ with no lone pairs on the central atom will have a ______ molecular shape.

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

Question 36

What is the predicted molecular geometry of the H₂O molecule according to the VSEPR model?

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

Question 37

What is the molecular geometry of NOCl as predicted by the VSEPR model?

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

Question 38

What is the molecular geometry of ClF₂⁻ as predicted by the VSEPR model?

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

Question 39

According to the VSEPR model, the molecular geometry of the carbonate ion, CO₃²⁻, is

A)square planar.
B)tetrahedral.
C)pyramidal.
D)trigonal planar.
E)octahedral.

Question 40

What is the molecular geometry of the thiocyanate anion, SCN⁻, as predicted by the VSEPR model? (Carbon is the central atom.)

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

Question 41

Which one of the following pure substances will exhibit hydrogen bonding?

A)CH₄
B)H₂C=CH₂
C)H₂O
D)CHCl₃
E)CHF₃

Question 42

What is the predicted O-C-O bond angle in CO₂?

A)60°
B)90°
C)109.5°
D)120°
E)180°

Question 43

Which of the following atoms does not participate in hydrogen bonding?

A)S
B)O
C)F
D)N
E)H

Question 44

Place the following in order of decreasing electronegativity. Mg Cl F

A)Mg > Cl > F
B)F > Cl > Mg
C)Cl > F > Mg
D)Cl > Mg > F
E)F > Mg > Cl

Question 45

Which substance will exhibit hydrogen bonding between molecules?

A)(CH₃)₃N
B)CH₃-O-CH₃
C)CH₃CH₂-OH
D)CH₃CH₂-F
E)HI

Question 46

Place the following in order of increasing electronegativity. N As K Ca

A)K < Ca < N < As
B)N < As < Ca < K
C)As < Ca < K < N
D)N < K < Ca < As
E)K < Ca < As < N

Question 47

The strongest intermolecular interactions between ethyl alcohol (CH₃CH₂OH) molecules arise from

A)dipole-dipole forces.
B)London dispersion forces.
C)hydrogen bonding.
D)ion-dipole interactions.
E)carbon-oxygen bonds.

Question 48

Which is the most reasonable prediction for the Cl-N-Cl bond angle in NCl₃?

A)120°
B)111°
C)109.5°
D)107°
E)90°

Question 49

Which of the following is defined as the attractive forces between polar molecules? I.dispersion forces
II)dipole-dipole interactions
Ion-dipole interactions

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

Question 50

Predict the molecular geometry and polarity of the SO₂ molecule.

A)linear, polar
B)linear, nonpolar
C)bent, polar
D)bent, nonpolar
E)trigonal planar, polar

Question 51

Predict the molecular geometry and polarity of the CS₂ molecule.

A)linear, polar
B)linear, nonpolar
C)tetrahedral, nonpolar
D)bent, nonpolar
E)bent, polar

Question 52

Which is the most reasonable prediction for the H-N-H bond angle in NH₃?

A)90°
B)109.5°
C)120°
D)107°
E)105°

Question 53

According to the VSEPR model, what is the predicted Cl-C-Cl bond angle in CCl₄?

A)90°
B)109.5°
C)120°
D)145°
E)180°

Question 54

Place the following in order of increasing electronegativity. Se K Cl

A)Cl < Se < K
B)K < Se < Cl
C)K < Cl < Se
D)Se < Cl < K
E)Cl < K < Se

Question 55

Which is the most reasonable prediction for the H-O-H bond angle in H₂O?

A)90°
B)109.5°
C)120°
D)107°
E)105°

Question 56

Place the following in order of increasing electronegativity. Cs O S

A)O < S < Cs
B)S < O < Cs
C)Cs < S < O
D)Cs < O < S
E)O < Cs < S

Question 57

Which one of the following molecules is polar?

A)CH₄
B)CHBr₃
C)F₂
D)CBr₄
E)CO₂

Question 58

Which substance should exhibit hydrogen bonding in the liquid phase?

A)PH₃
B)He
C)H₂S
D)CH₄
E)CH₃OH

Question 59

Which is the most reasonable prediction for the H-C-H bond angle in CH₄?

A)90°
B)109.5°
C)120°
D)107°
E)105°

Question 60

Which one of the following molecules is nonpolar?

A)NH₃
B)OF₂
C)CH₃Cl
D)H₂O
E)BeCl₂

Question 61

In which of the following compounds will the molecules not form hydrogen bonds with each other?

A)
B)
C)
D)

Question 62

Ammonia's unusually high melting point is the result of

A)dipole-dipole forces.
B)London dispersion forces.
C)hydrogen bonding.
D)covalent bonding.
E)ionic bonding.

Question 63

Helium atoms do not combine to form He₂ molecules, yet He atoms do attract one another weakly through

A)dipole-dipole forces.
B)ion-dipole forces.
C)dispersion forces.
D)dipole-induced dipole forces.
E)hydrogen bonding.

Question 64

Which kinds of intermolecular forces exist between propane molecules? I.dispersion forces
II)dipole-dipole interactions
Ion-dipole interactions

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

Question 65

At a temperature of 27 K, neon condenses due to

A)dipole-dipole forces.
B)London dispersion forces.
C)hydrogen bonding.
D)covalent bonding.
E)intramolecular forces.

Question 66

Octane is a component of fuel used in internal combustion engines.The dominant intermolecular forces in octane are

A)dipole-dipole forces.
B)London dispersion forces.
C)hydrogen bonding.
D)covalent bonds.
E)carbon-hydrogen bonds.

Question 67

The strongest intermolecular interactions between pentane (C₅H₁₂) molecules arise from

A)dipole-dipole forces.
B)London dispersion forces.
C)hydrogen bonding.
D)ion-dipole interactions.
E)carbon-carbon bonds.

Question 68

Which of the following pure substances has the strongest dispersion forces?

A)C₄H₁₀
B)C₅H₁₂
C)C₆H₁₄
D)C₇H₁₆
E)C₈H₁₈

Question 69

Which one of the following pure substance has both dispersion forces and dipole-dipole forces?

A)HCl
B)BCl₃
C)Br₂
D)H₂
E)CO₂

Question 70

For which of the following pure substances are the intermolecular interactions entirely due to dispersion forces?

A)C₂H₆
B)CH₃OCH₃
C)NO₂
D)H₂S
E)Ca(NO₃)₂

Question 71

The strongest intermolecular interactions between hydrogen fluoride (HF) molecules arise from

A)dipole-dipole forces.
B)London dispersion forces.
C)hydrogen bonding.
D)ion-dipole interactions.
E)ionic bonds.