Deck 10: The Shapes of Molecules

Question 1

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

Answer 1

ClO₃^-

Question 2

Which one of the following Lewis structures is definitely incorrect?

A) NO

B) HCN

C) NO₂^-

D) SO₃^2-

E) PCl₅

Answer 2

HCN

Question 3

Which one of the following Lewis structures is definitely incorrect?

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

Answer 3

E

Question 4

Which one of the following Lewis structures is definitely incorrect?

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

Question 5

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

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

Question 6

How many resonance structures are possible for NO₃^-?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 7

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

A)
B)
C)
D)
E) None of the above is correct.

Question 8

In which one of the following molecules are all the bonds single?

A) O₃
B) POCl₃
C) CO
D) COCl₂
E) N₂H₄

Question 9

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-

Question 10

Select the correct Lewis structure for nitrogen trifluoride, NF₃.

A)
B)
C)
D)
E)

Question 11

In carbon disulfide, how many lone pairs of electrons are on each sulfur atom?

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

Question 12

How many electron pairs are shared between the carbon atoms in C₂H₄?

A) 5
B) 4
C) 3
D) 2
E) 1

Question 13

Which one of the following molecules contains a double bond?

A) N₂
B) PCl₅
C) CH₂O
D) C₂H₂
E) I₂

Question 14

Select the best Lewis structure for ClCN.

A)
B)
C)
D)
E)

Question 15

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

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

Question 16

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

A)
B)
C)
D)
E) None of the above is correct.

Question 17

Select the best Lewis structure for P₂I₄.

A)
B)
C)
D)
E) None of the above structures is suitable for P₂I₄.

Question 18

In neutral molecules, how many bonds are commonly formed by nitrogen? And how many by oxygen?

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

Question 19

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

A)
B)
C)
D)
E) None of the above is correct.

Question 20

Select the correct Lewis structure for TeBr₂.

A)
B)
C)
D)
E)

Question 21

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 22

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

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

Question 23

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 24

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 25

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

A) NH₃
B) CO₂
C) SF₆
D) O₂
E) CO₃^2-

Question 26

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 27

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?

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 28

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

A)
B)
C)
D)
E)

Question 29

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

A) 120° only
B) 90° only
C) 180° only
D) 60° and 90° only
E) 90°, 120°, and 180°

Question 30

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

A) SF₆
B) SO₄^2-
C) O₃
D) BeCl₂
E) AlCl₄^-

Question 31

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

A)
B)
C)
D)
E)

Question 32

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 the above

Question 33

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

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

Question 34

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

A)
B)
C)
D)
E)

Question 35

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 36

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 37

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

A)
B)
C)
D)
E)

Question 38

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 39

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 40

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 41

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 the above

Question 42

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 43

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 44

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 45

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 46

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 47

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

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

Question 48

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 49

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 50

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 51

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 52

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 53

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 54

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 55

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 56

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 57

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

A) linear
B) bent
C) angular
D) trigonal
E) none of the above

Question 58

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 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 the above

Question 60

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 61

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 the above

Question 62

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 63

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

A) PCl₃
B) BF₄^-
C) XeF₄
D) BrF₅
E) H₃O⁺

Question 64

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 65

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 66

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 67

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 68

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 69

Predict the smallest actual bond angle 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 70

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°

Question 71

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 72

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 73

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 74

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 75

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 76

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 77

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 78

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.)

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

Question 79

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 80

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°