Deck 8: Basic Concepts of Chemical Bonding

Question 1

For the questions that follow, consider the BEST Lewis structures of the following ox_yanions:
There can be four equivalent best resonance structures of .

A) (i)
B) (ii)
C) (iii)
D) (iv)
E) (v)

Answer 1

(iv)

Question 2

The diagram below is the Born- huber cycle for the formation of crystalline potassium fluoride.
Which energy change corresponds to the first ionization energy of potassium?

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

Answer 2

3

Question 3

Which ion below has a noble gas electron configuration?

A) Be²⁺
B) N^2-
C) C²⁺
D) B²⁺
E) Li²⁺

Answer 3

Be²⁺

Question 4

Which two bonds are most similar in polarity?

A) B-F and Cl-F
B) O-F and Cl-F
C) Al-Cl and I-Br
D) Cl-Cl and Be-Cl
E) I-Br and Si-Cl

Question 5

Which atom can accommodate an octet of electrons, but doesn't necessarily have to accommodate an octet?

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

Question 6

Which of the following does not have eight valence electrons?

A) Xe
B) Rb⁺
C) Ca⁺
D) Br^-
E) All of the above have eight valence electrons.

Question 7

A valid Lewis structure of _ _ cannot be drawn without violating the octet rule.

A) CF₄
B) SO₃^2-
C) NF₃
D) SO₂
E) BeH₂

Question 8

Of the atoms below, is the least electronegative.

A) Rb
B) F
C) Ca
D) Cl
E) Si

Question 9

In the nitrite ion (NO₂^- ), .

A) one bond is a double bond and the other is a single bond
B) both bonds are single bonds
C) both bonds are the same
D) both bonds are double bonds
E) there are 20 valence electrons

Question 10

Of the atoms below, is the most electronegative.

A) Rb
B) Cl
C) Si
D) Ca
E) S

Question 11

Lattice energy is .

A) the energy required to produce one mole of an ionic compound from its constituent elements in their standard states
B) the energy required to convert a mole of ionic solid into its constituent ions in the gas phase
C) the sum of electron affinities of the components in an ionic solid
D) the energy given off when gaseous ions combine to form one mole of an ionic solid
E) the sum of ionization energies of the components in an ionic solid

Question 12

The Lewis structure of N₂H₂ shows .

A) each hydrogen has one nonbonding electron pair
B) a nitrogen- nitrogen single bond
C) each nitrogen has two nonbinding electron pairs
D) a nitrogen- nitrogen triple bond
E) each nitrogen has one nonbinding electron pair

Question 13

Given that the average bond energies for C- H and C- Br bonds are 413 and 276 kJ/mol, respectively, the heat of atomization of bromoform (CHBr₃) is _ kJ/mol.

A) 1241
B) 1378
C) - 689
D) 689
E) - 1378

Question 14

Of the ions below, only has a noble gas electron configuration.

A) S^3-
B) Cl^-
C) I⁺
D) O²⁺
E) K^-

Question 15

To convert from one resonance structure to another, .

A) neither electrons nor atoms can be moved
B) electrons and atoms can both be moved
C) only atoms can be moved
D) electrons must be added
E) only electrons can be moved

Question 16

For the questions that follow, consider the BEST Lewis structures of the following ox_yanions:
(i) NO₂^-
(ii) NO₃^-
(iii) SO₃^2-
(iv) SO₄^2-
(v) BrO₃^-
In which of the ions do all X- O bonds (X indicates the central atom) have the same length?

A) none
B) all
C) (i) and (ii)
D) (iii) and (v)
E) (iii), (iv), and (v)

Question 17

Of the atoms below, is the most electronegative.

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

Question 18

The chloride of which of the following metals should have the greatest lattice energy?

A) potassium
B) lithium
C) rubidium
D) sodium
E) cesium

Question 19

Of the following, cannot accommodate more than an octet of electrons.

A) O
B) As
C) S
D) I
E) P

Question 20

Resonance structures differ by .

A) placement of atoms only
B) placement of electrons only
C) number of electrons only
D) number and placement of electrons
E) number of atoms only

Question 21

A valid Lewis structure of _ _ cannot be drawn without violating the octet rule.

A) NF₃
B) SeF₄
C) SiF₄
D) PO₄^3-
E) CF₄

Question 22

The type of compound that is most likely to contain a covalent bond is _.

A) one that is composed of only nonmetals
B) one that is composed of a metal from the far left of the periodic table and a nonmetal from the far right of the periodic table
C) held together by the electrostatic forces between oppositely charged ions
D) a solid metal
E) There is no general rule to predict covalency in bonds.

Question 23

A valid Lewis structure of _ _ cannot be drawn without violating the octet rule.

A) ICl₅
B) SiF₄
C) CO₂
D) SO₂
E) NI₃

Question 24

The Lewis structure of the CO₃^2- ion is .

A)
B)

C)
D)

E)

Question 25

Using the Born- Haber cycle, the OH_f° of KBr is equal to _ _.

A) OH_f°[K (g)] + OH_f°[Br (g)] - I₁ - E(Br) + OH_lattice
B) OH_f°[K (g)] + OH_f°[Br (g)] + I₁(K) + E(Br) + OH_lattice
C) OH_f°[K (g)] - OH_f°[Br (g)] + I₁(K) - E(Br) + OH_lattice
D) OH_f°[K (g)] + OH_f°[Br (g)] + I₁(K) + E(Br) - OH_lattice
E) OH_f°[K (g)] - OH_f°[Br (g)] - I₁(K) - E(Br) - OH_lattice

Question 26

Of the possible bonds between carbon atoms (single, double, and triple), _.

A) a double bond is longer than a triple bond
B) a single bond is stronger than a double bond
C) a triple bond is longer than a single bond
D) a double bond is stronger than a triple bond
E) a single bond is stronger than a triple bond

Question 27

For resonance forms of a molecule or ion, .

A) there cannot be more than two resonance structures for a given species
B) the observed structure is an average of the resonance forms
C) all the resonance structures are observed in various proportions
D) the same atoms need not be bonded to each other in all resonance forms
E) one always corresponds to the observed structure

Question 28

Which of the following names is/are correct for the compound SnCl₄?

A) tin chloride and tin (II) tetrachloride
B) tin (IV) tetrachloride
C) tin tetrachloride and tin (IV) chloride
D) tin (II) chloride and tin (IV) chloride
E) tin chloride

Question 29

Dynamite .

A) is made of nitroglycerine and an absorbent such as diatomaceous earth
B) was invented by Alfred Nobel
C) is a much safer explosive than pure nitroglycerine
D) is an explosive
E) all of the above

Question 30

Bond enthalpy is .

A) always zero
B) always positive
C) sometimes positive, sometimes negative
D) always negative
E) unpredictable

Question 31

The bond length in an HI molecule is 1.61 Å and the measured dipole moment is 0.44 D. What is the magnitude (in units of e) of the negative charge on I in HI?
(1 debye = 3.34 × 10^{- 34} coulomb- meters; ; e=1.6 × 10^{- 19} coulombs)

A) 1.6 × 10^{- 19}
B) 1
C) 0.057
D) 0.22
E) 9.1

Question 32

Of the bonds below, is the least polar.

A) Na, S
B) P, S
C) Si, Cl
D) C, F
E) Na, Cl

Question 33

A valid Lewis structure of _ _ cannot be drawn without violating the octet rule.

A) ClF₃
B) SO₃
C) CCl₄
D) CO₂
E) PCl₃

Question 34

The central atom in _ _ does not violate the octet rule.

A) SF₄
B) CF₄
C) KrF₂
D) XeF₄
E) ICl₄^-

Question 35

Which of the following has the bonds correctly arranged in order of increasing polarity?

A) N-F, Be-F, Mg-F, O-F
B) Be-F, Mg-F, N-F, O-F
C) O-F, N-F, Be-F, Mg-F
D) Mg-F, Be-F, N-F, O-F
E) O-F, Be-F, Mg-F, N-F

Question 36

The central atom in _ violates the octet rule.

A) NH₃
B) AsF₃
C) BF₃
D) SeF₂
E) CF₄

Question 37

In which of the molecules below is the carbon- carbon distance the shortest?

A) H₃C- CH₃
B) H₃C- CH₂- CH₃
C) H- C≡C- H
D) H₂C=CH₂
E) H₂C=C=CH₂

Question 38

Of the molecules below, the bond in is the most polar.

A) HF
B) HI
C) H₂
D) HCl
E) HBr

Question 39

A valid Lewis structure of _ _ cannot be drawn without violating the octet rule.

A) SbF₃
B) SO₄^2-
C) NF₃
D) PF₃
E) IF₃

Question 40

Which of the following has eight valence electrons?

A) Cl^-
B) Kr
C) Ti⁴⁺
D) Na⁺
E) all of the above

Question 41

The electron configuration that corresponds to the Lewis symbol, :

Question 42

Which of the following names is/are correct for the compound TiO₂?

A) titanium oxide
B) titanium (IV) dioxide
C) titanium dioxide and titanium (IV) oxide
D) titanium (II) oxide
E) titanium oxide and titanium (IV) dioxide

Question 43

The electron configuration of the S^2- ion is .

A) [Ne]3s²3p⁶
B) [Ar]3s²3p²
C) [Ar]3s²3p⁶
D) [Ne]3s²3p²
E) [Kr]3s²2p^{- 6}

Question 44

The diagram below is the Born- huber cycle for the formation of crystalline potassium fluoride.

Which energy change corresponds to the electron affinity of fluorine?

A) 1
B) 5
C) 4
D) 2
E) 6

Question 45

Alternative but equivalent Lewis structures are called _ _ .

Question 46

In a reaction, if the bonds in the reactants are stronger than the bonds in the product, the reaction is .

Question 47

Which halogen, bromine or iodine, will form the more polar bond with phophorus ?

Question 48

Which of the elements below has the largest electronegativity?

A) P
B) Mg
C) Na
D) Si
E) S

Question 49

Of the bonds C- N, C=N, and C÷N, the C- N bond is .

A) strongest/shortest
B) weakest/longest
C) weakest/shortest
D) strongest/longest
E) intermediate in both strength and length

Question 50

As the number of covalent bonds between two atoms increases, the distance between the atoms
And the strength of the bond between them _ _.

A) increases, increases
B) decreases, decreases
C) increases, decreases
D) decreases, increases
E) is unpredictable

Question 51

The strength of a covalent bond is measured by its .

Question 52

Dynamite consists of nitroglycerine mixed with .

A) diatomaceous earth or cellulose
B) potassium nitrate
C) damp KOH
D) TNT
E) solid carbon

Question 53

The principal quantum number of the electrons that are lost when tungsten forms a caton is

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

Question 54

Calculate the bond energy of C- F given that the heat of atomization of CHFClBr is 1502 kJ/mol, and that the bond energies of C- H, C- Br, and C- Cl are 413, 276, and 328 kJ/mol, respectively.

Question 55

Draw the Lewis structure of ICl₂⁺.

Question 56

From the information given below, calculate the heat of combustion of methane (CH₄) (in kJ/mol). Start by writing the balanced equation.

Question 57

Most explosives are compounds that decompose rapidly to produce products and a great deal of .

A) solid, gas
B) liquid, heat
C) gaseous, gases
D) gaseous, heat
E) soluble, heat

Question 58

Write the balanced chemical equation for the reaction for which OH°_rxn is the lattice energy for potassium bromide.

Question 59

Why don't we draw double bonds between the Be atom and the Cl atoms in BeCl₂?

A) That would give positive formal charges to the chlorine atoms and a negative formal charge to the beryllium atom.
B) That would result in more than eight electrons around each chlorine atom.
C) That would result in the formal charges not adding up to zero.
D) There aren't enough electrons.
E) That would result in more than eight electrons around beryllium.

Question 60

Give the electron configuration of Cu²⁺.

Question 61

For a given arrangement of ions, the lattice energy increases as ionic radius and as ionic charge .

A) decreases, increases
B) decreases, decreases
C) increases, decreases
D) increases, increases
E) This cannot be predicted.

Question 62

How many unpaired electrons are there in the Lewis structures of a N^3- ion?

A) 0
B) 1
C) 2
D) 3
E) This cannot be predicted.

Question 63

Electronegativity _ from left to right within a period and _ from top to bottom within a group.

A) increases, increases
B) stays the same, increases
C) decreases, increases
D) increases, stays the same
E) increases, decreases

Question 64

The formal charge on sulfur in SO₄^2- is , where the Lewis structure of the ion is:

A) 0
B) - 4
C) - 2
D) +4
E) +2

Question 65

Using the table of bond dissociation energies, the OH for the following reaction is kJ.

A) - 359
B) - 223
C) 359
D) 208
E) 223

Question 66

Which of the following would have to lose two electrons in order to achieve a noble gas electron configuration ?

A) O, Se
B) Sr, O, Se
C) Sr
D) Na
E) Br

Question 67

What is the maximum number of double bonds that a carbon atom can form?

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

Question 68

A nonpolar bond will form between two _ _ atoms of electronegativity.

A) identical, equal
B) similar, different
C) different, opposite
D) different, different
E) identical, different

Question 69

Using the table of bond dissociation energies, the OH for the following gas- phase reaction is
KJ)

A) - 44
B) - 38
C) 304
D) 38
E) 2134

Question 70

Based on the octet rule, iodine most likely forms an _ ion.

A) I^4-
B) I²⁺
C) I⁺
D) I⁴⁺
E) I^-

Question 71

Which of the following would have to gain two electrons in order to achieve a noble gas electron configuration _ ?
O Sr Na Se Br

A) Br
B) Sr, O, Se
C) Sr
D) O, Se
E) Na

Question 72

The ion ICI₄^- has _ valence electrons.

A) 34
B) 8
C) 35
D) 36
E) 28

Question 73

Determining lattice energy from Born- Haber cycle data requires the use of .

A) Avogadro's number
B) the octet rule
C) Coulomb's law
D) Hess's law
E) Periodic law

Question 74

How many single covalent bonds must a silicon atom form to have a complete octet in its valence shell?

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

Question 75

The formal charge on carbon in the molecule below is .

A) +1
B) +2
C) +3
D) - 1
E) 0

Question 76

In the Lewis symbol for a fluorine atom, there are paired and unpaired electrons.

A) 4,1
B) 4, 2
C) 2, 5
D) 0, 5
E) 6, 1

Question 77

How many unpaired electrons are there in an O^2- ion?

A) 0
B) 1
C) 2
D) 3
E) This cannot be predicted.

Question 78

A covalent bond between the same two atoms is the longest.

A) triple
B) single
C) double
D) They are all the same length.
E) strong

Question 79

What is the electron configuration for the Co²⁺ ion?

A) [Ar]4s²3d⁹
B) [Ar]4s⁰3d⁷
C) [Ar]4s¹3d⁶
D) [Ne]3s²3p¹⁰
E) [Ar]4s⁰3d⁵

Question 80

How many equivalent resonance forms can be drawn for CO₃^2- - (carbon is the central atom)?

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