Deck 10: The Shapes of Molecules

Question 1

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)SO₃^2-

Answer 1

SO₃^2-

Question 2

Select the correct Lewis structure for TeBr₂.

A)a
B)b
C)c
D)d
E)e

Answer 2

e

Question 3

The formal charges on Cl and O in the structure shown for the ClO^- ion are,respectively

A)0 and -1
B)-1 and 0
C)1 and -2
D)-2 and 1
E)None of these choices is correct.

Answer 3

0 and -1

Question 4

Which one of the following Lewis structures is definitely incorrect?

A)a
B)b
C)c
D)d
E)e

Question 5

Select the Lewis structure for XeO₂F₂ which correctly minimizes formal charges.

A)a
B)b
C)c
D)d
E)e

Question 6

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

A)a
B)b
C)c
D)d
E)None of these choices is correct.

Question 7

Which one of the following Lewis structures is definitely incorrect?

A)a
B)b
C)c
D)d
E)e

Question 8

In which one of the following is the best Lewis structure a resonance structure? (central atoms are bold)

A)CO₂
B)ClO₃^-
C)COCl₂
D)NO₂⁺
E)HCN

Question 9

In the following Lewis structure for ClO₃F,chlorine has a formal charge of ____ and an oxidation number of ____.

A)7,7
B)7,-1
C)1,1
D)1,-1
E)1,7

Question 10

Which one of the following Lewis structures is definitely incorrect?

A)a
B)b
C)c
D)d
E)e

Question 11

Select the correct Lewis structure for nitrogen trifluoride,NF₃.

A)a
B)b
C)c
D)d
E)e

Question 12

Oxygen difluoride is a powerful oxidizing and fluorinating agent.Select its Lewis structure.

A)a
B)b
C)c
D)d
E)None of these choices is correct.

Question 13

Select the Lewis structure in which formal charges are minimized for the periodate anion,IO₄^-.

A)a
B)b
C)c
D)d
E)e

Question 14

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

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

Question 15

Select the best Lewis structure for ClCN.

A)a
B)b
C)c
D)d
E)e

Question 16

Select the best Lewis structure for P₂I₄.

A)a
B)b
C)c
D)d
E)None of these structures is suitable for P₂I₄.

Question 17

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

A)a
B)b
C)c
D)d
E)e

Question 18

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

A)a
B)b
C)c
D)d
E)e

Question 19

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

A)a
B)b
C)c
D)d
E)None of these choices is correct.

Question 20

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

A)a
B)b
C)c
D)d
E)None of these structures is suitable for SOCl₂.

Question 21

According to VSEPR theory,a molecule with the general formula AX₂ will have a ___ molecular shape.

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

Question 22

According to VSEPR theory,a molecule with the general formula AX₃E will have a _____ molecular shape.

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

Question 23

In which one of the following structures does the central atom have a formal charge of +2?

A)a
B)b
C)c
D)d
E)e

Question 24

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

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

Question 25

According to VSEPR theory,a molecule with the general formula AX₄E₂ will have a _____ molecular shape.

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

Question 26

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

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

Question 27

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

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

Question 28

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

A)NH₃
B)NH₄⁺
C)I₂
D)BH₄^-
E)SF₆

Question 29

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

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

Question 30

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

Question 31

According to VSEPR theory,a molecule with the general formula AX₆ will have a ______ molecular shape.

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

Question 32

According to VSEPR theory,a molecule with the general formula AX₅ will have a ______ molecular shape.

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

Question 33

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

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

Question 34

According to VSEPR theory,a molecule with the general formula AX₂E₃ will have a _____ molecular shape.

A)bent
B)linear
C)trigonal planar
D)T-shaped
E)trigonal pyramidal

Question 35

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

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

Question 36

Which of the following atoms can expand its valence shell when bonding?

A)N
B)C
C)O
D)P
E)Al

Question 37

According to VSEPR theory,a molecule with the general formula AX₂E will have a ______ molecular shape.

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

Question 38

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

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

Question 39

According to VSEPR theory,a molecule with the general formula AX₂E₂ will have a _____ molecular shape.

A)linear
B)bent
C)trigonal planar
D)tetrahedral
E)see-saw

Question 40

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

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

Question 41

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

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

Question 42

Which one of the following molecules and ions will have a planar geometry?

A)PCl₃
B)BF₄^-
C)XeF₄
D)BrF₅
E)H₃O⁺

Question 43

What is the molecular shape of BCl₃ as predicted by the VSEPR theory?

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

Question 44

What is the molecular shape of SCl₃F as predicted by the VSEPR theory?

A)linear
B)bent
C)see-saw
D)T-shaped
E)trigonal pyramidal

Question 45

Use VSEPR theory to decide which one of the following molecules and ions will definitely have at least one 90° bond angle in it.(In each case except water,the central atom is the first one in the formula. )

A)AlCl₄^-
B)NH₃
C)PCl₅
D)CO₂
E)H₂O

Question 46

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

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

Question 47

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

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

Question 48

Predict the ideal bond angles in GeCl₄ using the molecular shape given by the VSEPR theory.

A)90°
B)109°
C)120°
D)180°
E)< 90°

Question 49

Use VSEPR theory to predict the electron group arrangement around iodine,the central atom in the ion IF₂^-.

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

Question 50

What is the molecular shape of ClO₃F as predicted by the VSEPR theory?

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

Question 51

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

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

Question 52

What is the molecular shape of BeH₂ as predicted by the VSEPR theory?

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

Question 53

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

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

Question 54

What is the molecular shape of ClF₂^- as predicted by the VSEPR theory?

A)linear
B)bent
C)see-saw
D)T-shaped
E)L-shaped

Question 55

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

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

Question 56

Use VSEPR theory to decide which one of the following ions and molecules is likely to be planar.(The central atom is always first in the formula. )

A)BrF₃
B)H₃O⁺
C)PCl₃
D)SO₄^2-
E)SF₄

Question 57

What is the molecular symmetry around the carbons in CCl₂CH₂ as predicted by the VSEPR theory?

A)linear
B)trigonal planar
C)V-shaped
D)tetrahedral
E)trigonal pyramidal

Question 58

Use VSEPR theory to decide which one of the following molecules and ions will have a trigonal pyramidal geometry.(The central atom is always first in the formula. )

A)PCl₃
B)BF₃
C)SO₃
D)BrF₃
E)CO₃^2-

Question 59

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

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

Question 60

What is the molecular shape of NH₂Cl as predicted by the VSEPR theory?

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

Question 61

Draw all important resonance structures of the nitrate ion,NO₃^-

Question 62

List the three important ways in which molecules can violate the octet rule,and in each case draw one Lewis structure of your choice as an example.

Question 63

Predict the ideal bond angles in IF₂^- using the molecular shape given by the VSEPR theory.

A)60°
B)90°
C)109°
D)120°
E)180°

Question 64

Predict the ideal bond angles around nitrogen in N₂F₂ using the molecular shape given by the VSEPR theory.
(N is the central atom. )

A)90°
B)109°
C)120°
D)180°
E)between 120 and 180°

Question 65

Predict the actual bond angles in BrF₃ using the VSEPR theory.

A)more than 120°
B)exactly 120°
C)between 109° and 120°
D)between 90° and 109°
E)less than 90°

Question 66

Predict the ideal bond angles in AsCl₃ using the molecular shape given by the VSEPR theory.

A)90°
B)109°
C)120°
D)180°
E)between 110 and 120°

Question 67

Draw Lewis structures,showing all valence electrons,for the following species:
a.S^2-
b.CO
c.SO₂
d.CH₃OH

Question 68

Name and outline the concept which is introduced when more than one valid Lewis structure can be drawn for a given molecule or ion.Use appropriate diagrams of the formate ion (HCO₂^-,carbon is the central atom)to illustrate.

Question 69

Predict the ideal bond angles around carbon in C₂I₂ using the molecular shape given by the VSEPR theory.

A)90°
B)109°
C)120°
D)180°
E)None of these choices is correct.

Question 70

Which of the following has no net dipole moment?

A)N₂O
B)NF₃
C)H₂Se
D)TeO₃
E)CH₃Cl

Question 71

Which of the following molecules has a net dipole moment?

A)BeCl₂
B)SF₂
C)KrF₂
D)CO₂
E)CCl₄

Question 72

Draw Lewis structures which obey the octet rule,for the following atoms,molecules and ions,showing all valence electrons.Central atoms are shown in bold.
a.NH₃
b.O₃ (Hint: O₃ is not cyclic)
c.HCN
d.SO₃

Question 73

For the chlorate ion,ClO₃^-,draw two different valid Lewis structures,as follows:
a.a structure in which the octet rule is obeyed
b.a structure in which formal charges are minimized

Question 74

The Lewis structure of formaldehyde,CH₂O,is shown.Use VSEPR theory to predict the molecular geometry and the H-C-H bond angle.Outline your reasoning.

Question 75

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

A)CS₂
B)H₂S
C)CH₂Cl₂
D)PH₃
E)CH₂O

Question 76

Using SO₂ as an example,describe the sort of experimental data which might suggest that no single Lewis structure is an accurate representation of its bonding.

Question 77

Draw Lewis structures,showing all valence electrons,for:
a.N
b.Br^-
c.O₂
d.SO₄^2-

Question 78

Predict the actual bond angles in SF₃⁺ using the VSEPR theory.

A)more than 120°
B)exactly 120°
C)between 109° and 120°
D)between 90° and 109°
E)less than 90°

Question 79

Predict the actual bond angle in SeCl₂ using the VSEPR theory.

A)more than 120°
B)between 109° and 120°
C)between 90° and 109°
D)exactly 90°
E)less than 90°

Question 80

Predict the ideal bond angles in FNO using the molecular shape given by the VSEPR theory.

A)90°
B)109°
C)120°
D)180°
E)between 120 and 180°