Deck 9: Bonding and Molecular Structure

Question 1

Which of the following is the correct Lewis dash formula for carbon diselenide?

A)
B)
C)
D)
E)

Answer 1

Question 2

Which of the following Lewis structures for nitrogen oxides is incorrect?

A) N₂O.
B) N₂O₄.
C) N₂O₃.
D) N₂O₅.
E) All of these are incorrect structures.

Answer 2

N₂O₃.

Question 3

What is the total number of electrons (both lone and bond pairs) in the Lewis structure of SO₄2-?

A) 18
B) 20
C) 32
D) 24
E) 22

Answer 3

32

Question 4

Which of the following molecules or ions are isoelectronic: SO₃, NF₃, NO₃^-, CO₃^2-?

A) SO₃ and NF₃
B) NF₃ and CO₃^2-
C) SO₃, NF₃ and CO₃^2-
D) SO₃, NO₃^- and CO₃^2-
E) SO₃, NF₃, NO₃^-, and CO₃^2-

Question 5

Which of the following is a correct Lewis structure for H₂SO₄?

A)
B)
C)
D)
E)

Question 6

How many valence electrons are present in the Lewis formula for the chlorite ion, Cl₂^-?

A) 26
B) 18
C) 24
D) 20
E) 22

Question 7

Which is the best Lewis structure of CH₂FCO₂H (connectivity correct as given)?

A)
B)
C)
D)
E) none of these is acceptable

Question 8

How many lone pairs of electrons are assigned to the carbon atom in CO?

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

Question 9

Which of the following molecules or ions will have a Lewis structure most like that of phosphorus trichloride, PCl₃?

A) ClO₃^-
B) SO₃
C) CO₃^2-
D) BF₃
E) Cl₂CO

Question 10

The correct Lewis structure for Cl₂CO is (the 2 Cl's and the O are bound to the C and not to each other):

A)
B)
C)
D)
E) none of these

Question 11

Which combination of atoms is most likely to produce a compound with ionic bonds?

A) B and C
B) S and O
C) N and F
D) Si and Cl
E) Mg and O

Question 12

Which combination of atoms is most likely to produce a compound with covalent bonds?

A) K and Br
B) Al and S
C) S and Cl
D) Sn and F
E) Li and I

Question 13

If two or more species have the same number of electrons, resulting in similar Lewis structures, they are said to be ____.

A) isoelectronic
B) resonant structures
C) ionic
D) neutral
E) covalent

Question 14

Which of the following pairs of compounds contains ionic bonds?

A) KI and O₃
B) NaF and H₂O
C) PCl₅ and HF
D) Na₂SO₃ and BH₃
E) RbBr and MgS

Question 15

Which of the following is the correct Lewis structure for the sulfate ion?

A)
B)
C)
D)
E)

Question 16

Which of the following is a correct Lewis structure for oxygen?

A)
B)
C)
D)
E) $: \mathrm { O } \equiv \mathrm { O } :$

Question 17

Which of the following has a Lewis structure similar to OCS?

A) NH₂−
B) O₃
C) N₂O⁺
D) SO₂
E) ClO₂−

Question 18

How many hydrogen atoms are needed to complete the following hydrocarbon structure?

A) 10
B) 12
C) 8
D) 14
E) 6

Question 19

Which of the following is the Lewis electron dot structure for carbon monoxide?

A) $: \mathrm { C } \equiv \mathrm { O } :$
B)
C)
D) $\mathrm{C} \equiv \mathrm{Ö:}$
E) $\text { :c?-ö: }$

Question 20

Which of the following groups of molecules contains no ionic compounds?

A) HCN, NO₂, and Ca(NO₃)₂
B) PCl₅, LiBr, and Zn(OH)₂
C) KOH, CCl₄, and SF₄
D) NaH, CaF₂, and NaNH₂
E) CH₂O, H₂S, and NH₃

Question 21

When both of the electrons in a molecular bond originate from the same atom, the bond is called a(n)

A) sigma bond.
B) coordinate covalent bond.
C) pi bond.
D) metallic bond.
E) ionic bond.

Question 22

One resonance structure for OCN^- ion is drawn below. What is the formal charge on each atom?

A) O atom = 0, C atom = 0, and N atom = 0
B) O atom = 0, C atom = 0, and N atom = -1
C) O atom = -1, C atom = 0, and N atom = 0
D) O atom = -1, C atom = -1, and N atom = +1
E) O atom = +1, C atom = 0, and N atom = -2

Question 23

Which of the following has an incomplete octet in its Lewis structure?

A) SO₂
B) F₂
C) NO₂
D) ICl
E) CO₂

Question 24

Which of the following elements is most likely to form a molecular structure that disobeys the octet rule?

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

Question 25

The molecule H₂S has

A) 2 bonding pairs and 3 lone pairs
B) 2 bonding pairs and 2 lone pairs
C) 3 bonding pairs and 1 lone pair
D) 3 bonding pairs and 3 lone pairs
E) none of these

Question 26

How many different molecules have the molecular formula C₆H₁₄?

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

Question 27

The nitrogen atom in the cyanide ion, CN^-, is surrounded by:

A) one single bond and three lone pairs of electrons.
B) one double bond and one lone pair of electrons.
C) one double bond and two lone pairs of electrons.
D) one triple bond and one lone pair of electrons.
E) one triple bond and no lone pairs of electrons.

Question 28

Which of the following exhibits resonance?

A) SCl₄
B) H₂O
C) SO₂
D) BH₃
E) none

Question 29

Which of the following elements is able to form a molecular structure that exceeds the octet rule?

A) C
B) N
C) O
D) F
E) Cl

Question 30

The central atom in N₂O is a nitrogen atom. This nitrogen atom is surrounded by

A) two single bonds and two lone pairs of electrons.
B) two single bonds and one lone pair of electrons.
C) one single bond, one double bond, and one lone pairs of electrons.
D) one single bond, one double bond, and one lone pair of electrons.
E) two double bonds and no lone pairs of electrons.

Question 31

Which of the following are the correct resonance structures for the formate ion, HCO₂^-?

A) 1 and 2
B) 2 and 3
C) 3 and 4
D) 1, 3, and 4
E) 2, 3, and 4

Question 32

What is the formal charge on each atom in dichloromethane, CH₂Cl₂?

A) C atom = 0, each H atom = 0, and each Cl atom = 0
B) C atom = -2, each H atom = +1, and two Cl atoms = 0
C) C atom = +4, each H = -1, and each Cl atom = -1
D) C atom = +4, each H = +1, and each Cl atom = -1
E) C atom = -4, each H = +1, and each Cl atom = +1

Question 33

Which of the following molecules or ions does not have one or more resonance structures?

A) O₃
B) OCN^-
C) SO₂
D) H₂CO
E) NO₃^-

Question 34

What is the formal charge on the O₂ atom in the following Lewis structure?

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

Question 35

What is the formal charge of the oxygen atom in the Lewis structure for cyanate shown below?

A) 0
B) −2
C) +1
D) −1
E) 2

Question 36

What is the formal charge on the carbon atom in CO?

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

Question 37

How many lone pairs are present around the central atom in the Lewis structure of SF₆?

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

Question 38

Which of the following is not a valid resonance structure for N₃^-?

A)
B)
C)
D)
E) all are correct

Question 39

The Lewis structure of which of the following molecules violates the octet rule?

A) SF₄
B) NF₃
C) OF₂
D) HF
E) SiF₄

Question 40

Which of the following are possible Lewis structures for a molecule with the formula C₂H₆O?

A) 1
B) 2
C) 3
D) 2 and 3
E) 1, 2, and 3

Question 41

Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of nitrogen trichloride, NCl₃.

A) The electron-pair geometry is linear, the molecular geometry is linear.
B) The electron-pair geometry is trigonal-planar, the molecular geometry is trigonal-planar.
C) The electron-pair geometry is trigonal-planar, the molecular geometry is bent.
D) The electron-pair geometry is tetrahedral, the molecular geometry is tetrahedral.
E) The electron-pair geometry is tetrahedral, the molecular geometry is trigonal-pyramidal.

Question 42

Which of the following is the correct Lewis structure of IF₃?

A)
B)
C)
D)
E)

Question 43

What is the molecular geometry around carbon atom C₁?

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

Question 44

Use VSEPR theory to predict the molecular geometry around either carbon atom in acetylene, C₂H₂.

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

Question 45

The central atom in SF₆ is surrounded by

A) six single bonds and no lone pairs of electrons.
B) six single bonds and one lone pair of electrons.
C) six single bonds and two lone pairs of electrons.
D) five single bonds, one double bond, and one lone pair of electrons.
E) four single bonds, two double bonds, and no lone pairs of electrons.

Question 46

Which of the following species has a Lewis structure similar to iodine tetrafluoride, IF₄^-?

A) XeF₄
B) SO₄^2-
C) PF₄⁺
D) SF₄
E) IO₄^-

Question 47

What is the bond angle in a trigonal planar molecule or ion?

A) 109°
B) 180°
C) 90°
D) 72°
E) 120°

Question 48

Use VSEPR theory to predict the molecular geometry of BrO₃^-.

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

Question 49

According to VSEPR theory, which of the following is the correct molecular geometry around the carbon atom in formaldehyde?

A) Linear
B) Bent
C) Trigonal-planar
D) Tetrahedral
E) Octahedral

Question 50

Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of xenon tetrafluoride, XeF₄.

A) The electron-pair geometry is tetrahedral, the molecular geometry is tetrahedral.
B) The electron-pair geometry is octahedral, the molecular geometry is tetrahedral.
C) The electron-pair geometry is tetrahedral, the molecular geometry is octahedral.
D) The electron-pair geometry is octahedral, the molecular geometry is square-planar.
E) The electron-pair geometry is square-planar, the molecular geometry is tetrahedral.

Question 51

What is the correct Lewis structure for SF₄?

A)
B)
C)
D)
E)

Question 52

Use VSEPR theory to predict the molecular geometry of BrF₅.

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

Question 53

Use VSEPR theory to predict the electron-pair geometry and the molecular geometry of boron tribromide, BBr₃.

A) The electron-pair geometry is trigonal-pyramidal, the molecular geometry is trigonal-pyramidal.
B) The electron-pair geometry is trigonal-planar, the molecular geometry is trigonal-planar.
C) The electron-pair geometry is trigonal-planar, the molecular geometry is bent.
D) The electron-pair geometry is tetrahedral, the molecular geometry is trigonal-pyramidal.
E) The electron-pair geometry is trigonal-pyramidal, the molecular geometry is t-shaped.

Question 54

Which of the following molecules or ions are likely to be free radicals: N₂O, NO, and NO₂?

A) N₂O only
B) NO only
C) NO₂ only
D) N₂O and NO
E) NO and NO₂

Question 55

What is the electron-pair geometry around an atom in a molecule or ion which is surrounded by two lone pairs of electrons and three single bonds.

A) trigonal bipyramidal
B) see-saw or distorted tetrahedron
C) T-shaped
D) linear
E) trigonal planar

Question 56

When you draw the Lewis structure for PF₂Cl₃, how many single bonds, double bonds, and lone pair electrons reside on the central phosphorus atom?

A) 5 single bonds, 0 double bonds, 0 lone pairs
B) 4 single bonds, 1 double bond, 0 lone pairs
C) 5 single bonds, 0 double bonds, 1 lone pair
D) 4 single bonds, 1 double bond, 1 lone pair
E) 3 single bonds, 2 double bonds, 0 lone pairs

Question 57

What is the molecular geometry around the nitrogen atom _{as per the valence shell electron-pair repulsion (VSEPR) theory?}? ​ ​

A) Trigonal pyramidal
B) Bent
C) Tetrahedral
D) See-saw or distorted tetrahedral
E) Trigonal planar

Question 58

According to VSEPR theory, which of the following is the correct statement concerning the electron-pair geometry and the molecular geometry of sulfur dioxide?

A) The electron-pair geometry is trigonal planar, and the molecular geometry is trigonal planar.
B) The electron-pair geometry is trigonal-planar, and the molecular geometry is bent.
C) The electron-pair geometry is tetrahedral, and the molecular geometry is bent.
D) The electron-pair geometry is tetrahedral, and the molecular geometry is linear.
E) The electron-pair geometry is trigonal bipyramidal, and the molecular geometry is linear.

Question 59

What is the molecular geometry around an atom in a molecule or ion which is surrounded by zero lone pairs of electrons and four single bonds.

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

Question 60

Use VSEPR theory to predict the molecular geometry around the nitrogen atom in nitrite ion, NO₂^-.

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

Question 61

Atoms having equal or nearly equal electronegativities are expected to form

A) no bonds
B) polar covalent bonds
C) nonpolar covalent bonds
D) ionic bonds
E) covalent bonds

Question 62

Determine the bond order of NO+?

A) 2
B) 1.5
C) 1
D) 2.5
E) 3

Question 63

What is the O−C−N bond angle in OCN^-?

A) 90°
B) 107°
C) 109.5°
D) 120°
E) 180°

Question 64

Which of the following compounds has polar covalent bonds: CCl₄, Cl₂, HCl, and KCl?

A) CCl₄ only
B) Cl₂ only
C) HCl and KCl
D) Cl₂ and KCl
E) CCl₄ and HCl

Question 65

What are the approximate H−N−H bond angles in NH₄⁺?

A) 109.5°
B) 120°
C) 109.5° and 120°
D) 90°
E) 90° and 120°

Question 66

Three nonequivalent Lewis structures for carbonyl sulfide, SCO, are given below. Use the concepts of formal charge and electronegativity to choose the structure that is the best representation. A B C

A) Structure A, because all the formal charges equal 0
B) Structure B, because all the formal charges equal 0
C) Structure C, because all the formal charges equal 0.
D) Structure A, because the negative formal charge resides on the most electronegative atom
E) Structure C, because the negative formal charge resides on the most electronegative atom

Question 67

Rank the following covalent bonds in order of decreasing polarity: C-H, N-H, O-H, and F-H.

A) F-H > O-H > N-H > C-H
B) O-H > F-H > N-H > C-H
C) N-H > F-H > O-H > C-H
D) C-H > N-H > O-H > F-H
E) C-H > F-H > O-H > N-H

Question 68

Place the following molecules in order from smallest to largest H−N−H bond angles: NH₄⁺, NH₃, and NH₂^-.

A) NH₄⁺ < NH₃ < NH₂^-
B) NH₄⁺ < NH₂^- < NH₃
C) NH₂^- < NH₃ < NH₄⁺
D) NH₂^- < NH₄⁺ < NH₃
E) NH₃ < NH₂^- < NH₄⁺

Question 69

Which of the following molecules is polar?

A) CS₂
B) SO₂
C) XeF₂
D) XeF₄
E) SO₃

Question 70

Electronegativity is a measure of _____.

A) the ability of a substance to conduct electricity
B) the charge on a polyatomic cation
C) the charge on a polyatomic anion
D) the ability of an atom in a molecule to attract electrons to itself
E) the oxidation number of an atom in a molecule or polyatomic anion

Question 71

Which of the following bonds would be the most polar?

A) N--C
B) N--Si
C) N--P
D) N--Al
E) N--Ga

Question 72

In molecules, as bond order increases,

A) both bond length and bond energy increase.
B) both bond length and bond energy decrease.
C) bond length increases and bond energy is unchanged.
D) bond length is unchanged and bond energy increases.
E) bond length decreases and bond energy increases.

Question 73

Which of the following is the approximate O−S−O bond angle in the sulfite ion, SO₃^2-?

A) 90°
B) 109.5°
C) 120°
D) 180°
E) 150°

Question 74

Three possible structures of C₂H₂Cl₂ are shown below. Which of these molecules are polar?

A) 1 only
B) 2 only
C) 3 only
D) 1 and 3
E) 2 and 3

Question 75

Choose which central atom in the following molecules is most electronegative.

A) PH₃
B) CH₄
C) H₂S
D) H₂O
E) NH₃

Question 76

Use Lewis structures to predict the bond order for a sulfur-oxygen bond in SO₃2-?

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

Question 77

Which of the following molecules is nonpolar?

A) sulfur dioxide, SO₂
B) hydrogen fluoride, HF
C) phosphorus trifluoride, PF₃
D) boron trifluoride, BF₃
E) iodine trichloride, ICl₃

Question 78

Based on electron-pair geometries, which of the following molecules has the smallest bond angle between any two adjacent atoms?

A) CH₄
B) H₂O
C) BH₃
D) PH₃
E) SF₆

Question 79

What are the approximate F−Br−F bond angles in BrF₅?

A) 90° and 180°
B) 109.5°
C) 90° and 120°
D) 120°
E) 180°

Question 80

Linus Pauling noticed that the energy of a polar bond is often greater than expected. He attributed the greater bond energy to

A) a coulombic attraction between atoms with partially positive and negative charges.
B) the greater bond lengths of the heteronuclear bonds.
C) one of the many unexplainable phenomena that scientists encounter.
D) the ability of heteronuclear species to form double and triple bonds.
E) the greater number of valence electrons found in heteronuclear molecules.