Deck 13: Bonding: General Concepts

Question 1

For the elements Cs, F, and Cl, the order of increasing electronegativity is

A) Cl < Cs < F.
B) Cs < Cl < F.
C) F < Cs < Cl.
D) F < Cl < Cs.
E) None of these

Answer 1

Cs < Cl < F.

Question 2

Based on electronegativities, which of the following would you expect to be most ionic?

A) N₂
B) CO₂
C) CF₄
D) CH₄
E) CaF₂

Answer 2

CaF₂

Question 3

Which of the following is nonpolar?

A) Cl₂O
B) CS₂
C) SF₄
D) IF₃
E) NCl₃

Answer 3

CS₂

Question 4

The electron pair in a C-F bond could be considered

A) an inadequate model because the bond is ionic.
B) closer to C because carbon has a lower electronegativity than fluorine.
C) closer to C because carbon has a larger radius and thus exerts greater control over the shared electron pair.
D) closer to F because fluorine has a higher electronegativity than carbon.
E) centrally located directly between the C and F.

Question 5

Which of the following bonds would be the most polar without being considered ionic?

A) C-O
B) Mg-O
C) O-O
D) Si-O
E) N-O

Question 6

Which of the following elements forms the most ionic bond with chlorine?

A) Kr
B) Ga
C) N
D) I
E) K

Question 7

Which of the following groups contains no ionic compounds?

A) KH, SrF₂, NaNH₂
B) KOH, CBr₄, SF₄
C) HCN, NO₂, Sr(NO₃)₂
D) CH₂O, H₂O, NBr₃
E) PCl₅, LiBr, Zn(OH)₂

Question 8

In the gaseous phase, which of the following diatomic molecules would be the most polar?

A) NaCl
B) CsF
C) NaF
D) LiF
E) CsCl

Question 9

Which of the following shows these molecules in order from most polar to least polar?

A) CF₂Cl₂ > CF₂H₂ > CCl₂H₂ > CH₄ = CCl₄
B) CH₄ > CF₂Cl₂ > CF₂H₂ > CCl₄ > CCl₂H₂
C) CF₂H₂ > CCl₂H₂ > CF₂Cl₂ > CH₄ = CCl₄
D) CF₂Cl₂ > CF₂H₂ > CCl₄ > CCl₂H₂ > CH₄
E) CH₄ > CF₂H₂ > CF₂Cl₂ > CCl₄ > CCl₂H₂

Question 10

Choose the compound with the most ionic bond.

A) LiCl
B) RbI
C) KCl
D) KF
E) NaCl

Question 11

Which of the following bonds would be the least polar and yet still be considered polar covalent?

A) Mg-O
B) Si-O
C) B-O
D) N-O
E) O-O

Question 12

What of the following shows the bonds in order of decreasing polarity?

A) N-Cl, P-Cl, As-Cl
B) As-Cl, P-Cl, N-Cl
C) P-Cl, As-Cl, N-Cl
D) P-Cl, N-Cl, As-Cl
E) As-Cl, N-Cl, P-Cl

Question 13

Which element listed below has the highest electronegativity?

A) K
B) Te
C) Br
D) I
E) Rb

Question 14

For the elements Rb, F, and O, the order of increasing electronegativity is

A) Rb < O < F.
B) Rb < F < O.
C) O < F < Rb.
D) F < Rb < O.
E) none of these.

Question 15

Which of the following statements is incorrect?

A) A molecule with very polar bonds can be nonpolar.
B) Ionic bonding results from the transfer of electrons from one atom to another.
C) Dipole moments result from the unequal distribution of electrons in a molecule.
D) Linear molecules cannot have a net dipole moment.
E) The electrons in a polar bond are found nearer to the more electronegative element.

Question 16

In which case is the bond polarity incorrect?

A) δ⁺ Cl-Br δ^-
B) δ⁺ Na-O δ^-
C) δ⁺ H-Br δ^-
D) δ⁺ Ca-H δ^-
E) δ⁺ C-O δ^-

Question 17

Atoms having greatly differing electronegativities are expected to form

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

Question 18

Which compound does not contain both polar covalent and ionic bonds?

A) Ca(CN)₂
B) NH₄ClO₃
C) CH₃OH
D) KOH
E) CsC₂H₃O₂

Question 19

As a general pattern, electronegativity is inversely related to

A) atomic size
B) polarity of the atom.
C) the number of neutrons in the nucleus.
D) ionization energy.
E) two of these.

Question 20

Which of the following bonds is the least polar?

A) H-N
B) H-C
C) H-O
D) H-F
E) All are the same.

Question 21

Choose the statement that best describes the PbCl₄ molecule in the gas phase.

A) The molecule is polar.
B) The bonds are nonpolar.
C) The molecule is polar with bond angles of about 109°.
D) The bond angles are all about 109°.
E) The molecule has a dipole moment.

Question 22

Which statement is correct?

A) H₂O is linear.
B) The molecule ClO₂ cannot be accurately described by a Lewis structure consistent with the octet rule.
C) The diatomic molecule Cl₂ is an example of a polar molecule.
D) The bonds in LiF have a more covalent character than those in F₂.
E) none of these

Question 23

Which of the following ionic compounds has the largest lattice energy; that is, which has the lattice energy most favorable to a stable lattice?

A) LiF
B) LiI
C) CsF
D) MgO
E) CsI

Question 24

Use the following electronegativity values to answer the question:

This molecule is the most polar.

A) CH₃Cl
B) C₂H₆
C) CO₂
D) CH₃CHO
E) none of these

Question 25

Which of the following molecules has a dipole moment?

A) PCl₃
B) BCl₃
C) Cl₂
D) SiCl₄
E) none of these

Question 26

Which of the following has a zero dipole moment?

A) SO₂
B) NO₂
C) PF₅
D) NH₃
E) HCN

Question 27

Which of the following has the smallest radius?

A) Se^2-
B) Sr²⁺
C) Br⁺
D) Kr
E) Rb⁺

Question 28

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

A) H₂O
B) H₂S
C) H₂Xe
D) All of these have a dipole moment.
E) None of these has a dipole moment.

Question 29

Consider the following molecules.
I. BF₃
II. CHBr₃ (C is the central atom.)
III. Br₂
IV. XeCl₂
V. CO
VI. SF₄
Select the molecule(s) that fit the given statement.These molecules have a zero net dipole moment.

A) III, V
B) III, IV, V
C) I, III, IV
D) I, III, IV, VI
E) none of them

Question 30

Which of the following molecules has a nonzero dipole moment?

A) CO₂
B) CBr₄
C) SiH₄
D) SO₃
E) PCl₃

Question 31

The first electron affinity value for oxygen is _______ and the second electron affinity value is ________.

A) favorable (exothermic), favorable (exothermic)
B) More information is needed.
C) favorable (exothermic), unfavorable (endothermic)
D) unfavorable (endothermic), favorable (exothermic)
E) unfavorable (endothermic), unfavorable (endothermic)

Question 32

Which of the following molecules has a zero dipole moment?

A) NCl₃
B) XeF₂
C) SCl₄
D) H₂S
E) ICl₃

Question 33

Calculate the lattice energy for LiF(s) given the following:

A) -650. kJ/mol
B) -1047 kJ/mol
C)800. kJ/mol
D) 285 kJ/mol
E) none of these

Question 34

Given the following information: calculate the net change in energy for the reaction 2Li(s) + 2HCl(g) → 2LiCl(s) + H₂(g)

A) -179 kJ
B) 362 kJ
C) -70. kJ
D) -572 kJ
E) None of these

Question 35

In the reaction between magnesium and sulfur, the magnesium atoms

A) share electrons with sulfur.
B) become part of polyatomic ions.
C) become anions.
D) become cations.

Question 36

Which of the following is polar?

A) PBr₃
B) SiF₄
C) SBr₆
D) KrF₂
E) BF₃

Question 37

Which of the following series is isoelectronic?

A) B, C, N, O
B) Sn, As, S, F
C) Na, K, Rb, Cs
D) S^2-, Cl^-, K⁺, Ca²⁺
E) F^-, Cl^-, K⁺, Rb⁺

Question 38

Which of the following molecules has a dipole moment?

A) SCl₆
B) CO₂
C) OF₂
D) BH₃
E) None of these has a dipole moment.

Question 39

Which of the following has the largest radius?

A) K⁺
B) Ar
C) S^2-
D) Ca²⁺
E) Cl^-

Question 40

Which of the following molecules has a dipole moment?

A) SF₄
B) CF₄
C) XeF₄
D) All of these have a dipole moment.
E) None of these has a dipole moment.

Question 41

Which of the following compounds contains only one unshared pair of valence electrons?

A) NaCl
B) NH₃
C) BeF₃
D) CH₄
E) H₂O

Question 42

Consider the compound crotonaldehyde, whose skeleton is
How many electrons must be shown in the Lewis structure of this molecule?

A) 32
B) 28
C) 18
D) 24
E) 12

Question 43

Given the following bond energies: estimate ΔH for the reaction H₂O₂ + CH₃OH → H₂CO + 2H₂O.

A) -145 kJ
B) +291 kJ
C) -291 kJ
D) +145 kJ
E) -287 kJ

Question 44

Estimate the bond energy of the N₂ molecule. for NH₃ = -46.0 kJ/mol
N-H bond energy = 391 kJ/mol
H-H bond energy = 432 kJ/mol

A) 1140 kJ/mol
B) 560 kJ/mol
C) 87 kJ/mol
D) 479 kJ/mol
E) 958 kJ/mol

Question 45

Choose the molecule with the strongest bond.

A) HBr
B) HCl
C) HF
D) HI

Question 46

Which of the following molecules contains a double bond?

A) CO₂
B) H₂O
C) NH₃
D) all
E) none

Question 47

What does X represent in the Lewis structure X=X?

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

Question 48

In which of the following compounds does the bond between the central atom and fluorine have the greatest ionic character?

A) SF₂
B) SeF₂
C) OF₂
D) SbF₃
E) AsF₃

Question 49

Choose the molecule with the strongest bond.

A) I₂
B) F₂
C) Br₂
D) Cl₂

Question 50

In the Lewis structure for elemental nitrogen, there is(are)

A) a triple bond between the nitrogens.
B) three unpaired electrons.
C) a double bond between the nitrogens.
D) a single bond between the nitrogens.
E) none of these

Question 51

Choose the molecule with the strongest bond.

A) HF
B) NH₃
C) H₂O
D) CH₄

Question 52

Which of the following molecules exhibits the greatest bond energy?

A) Cl₂
B) Br₂
C) F₂
D) I₂
E) all the same

Question 53

Using the following data reactions: calculate the energy of an H-Cl bond.

A) 518 kJ
B) 326 kJ
C) 856 kJ
D) 770 kJ
E) 428 kJ

Question 54

Use the following electronegativity values to answer the question:
C 2.5 Cl 3.2
H 2.2 N 3.0
O 3.4
This molecule shows the smallest number of lone pairs in its Lewis structure.

A) CH₃CHO
B) CO₂
C) CH₃Cl
D) C₂H₆
E) none of these

Question 55

Consider the compound crotonaldehyde, whose skeleton is
How many nonbonding electrons appear in the Lewis structure of this molecule?

A) 2
B) 4
C) 8
D) 10
E) 6

Question 56

Which of the following molecules and ions has a lone pair of electrons on the central atom?

A) PCl₅
B) XeO₄
C) BeCl₂
D) CH₃⁺
E) CH₃^-

Question 57

Using the following bond energies: estimate the heat of combustion for 1 mol of acetylene:

A) +365 kJ
B) 1228 kJ
C) -447 kJ
D) -1228 kJ
E) +447 kJ

Question 58

As the number of bonds between two carbon atoms increases, which one of the following decreases?

A) the number of electrons between the carbon atoms
B) the bond length
C) the bond energy
D) all of these
E) none of these

Question 59

Given the following information:
N₂ bond energy = 941 kJ/mol
F₂ bond energy = 154 kJ/mol
Calculate the N-F bond energy.

A) 113 kJ/mol
B) 268 kJ/mol
C) 66 kJ/mol
D) 317 kJ/mol
E) none of these

Question 60

In which pair do both compounds exhibit predominantly ionic bonding?

A) KF and O₃
B) PBr₅ and HF
C) NaF and H₂S
D) NaCl and SrO
E) Na₂SO₃ and BCl₃

Question 61

As indicated by Lewis structures, which of the following species could probably not exist as a stable molecule?

A) N₂H₆
B) N₂O₄
C) N₂H₂
D) N₂H₄
E) NH₃

Question 62

How many acceptable and equivalent resonance structures can be drawn for NO₃^-?

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

Question 63

For which compound is resonance required to describe the structure adequately?

A) PCl₃
B) CO₃^2-
C) HCN
D) NH₄⁺
E) none of these

Question 64

Draw the Lewis structures of the molecules below, and use them to answer the following questions.
I. BH₃
II. NO₂
III. SF₆
IV. O₃
V. PCl₅
Which of the molecules obeys the octet rule?

A) II
B) IV
C) III
D) V
E) I

Question 65

Which molecule or ion violates the octet rule?

A) I₃^-
B) PF₃
C) H₂O
D) NO₃^-
E) none of these

Question 66

How many of the following molecules and ions contain double or triple bonds?
N₂ H₂CO C₂H₄ C₂H₆ SCN^-

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

Question 67

Select the best Lewis structure for acetone, CH₃COCH₃.

A)
B)
C)
D)
E)

Question 68

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

A)
B)
C)
D)
E) All are valid.

Question 69

How many electrons are in the Lewis structure for SO₂?

A) 18
B) 20
C) 32
D) 16
E) 30

Question 70

Given the following Lewis structure:
How many electrons are shared between carbons 1 and 2?

A) 6
B) 2
C) 0
D) 8
E) 4

Question 71

When molten sulfur reacts with chlorine gas, a vile-smelling orange liquid forms that is found to have the empirical formula SCl. Which of the following could be the correct Lewis structure for this compound?

A)
B)
C)
D)
E)

Question 72

In the Lewis structure for I₃^-, there are _________ electrons around the central iodine atom.

A) 12
B) 4
C) 8
D) 10
E) none of these

Question 73

Complete the Lewis structure for the molecule This molecule has __________ single bonds and __________ multiple bonds.

A) 11, 2
B) 6, 3
C) 13, 0
D) 11, 5
E) 4, 2

Question 74

For which of the following can we not draw a stable Lewis structure?

A) PCl₅
B) OCl₆
C) SCl₆
D) All of these have stable Lewis structures.
E) None of these has a stable Lewis structure.

Question 75

As indicated by Lewis structures, which of the following would probably not exist as a stable molecule?

A) CH₂O
B) C₂H₂
C) CH₃O
D) C₃H₄
E) CH₃OH

Question 76

The Lewis structure for H₃BO₃ is

A)
B)
C)
D)
E)

Question 77

How many of the following exhibit resonance?
O₃ OCl₂ NF₃ CCl₄

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

Question 78

How many resonance structures does the molecule SO₂ have?

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

Question 79

Given the following Lewis structure:
How many unshared pairs of electrons are present in this molecule?

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

Question 80

Which species has an unpaired electron?

A) OH^-
B) N₂
C) CO
D) NO
E) none of these