Deck 9: Chemical Bonding I: the Covalent Bond

Question 1

Which one of the following is most likely to be an ionic compound?

A)ClF₃
B)FeCl₃
C)NH₃
D)PF₃
E)SO₃

Answer 1

FeCl₃

Question 2

Which of the following solids would have the lowest melting point?

A)KI
B)KBr
C)KCl
D)KF

Answer 2

KI

Question 3

Which one of the following is most likely to be a covalent compound?

A)Rb₂O
B)BaO
C)SrO
D)SeO₂
E)MnO₂

Answer 3

SeO₂

Question 4

Which one of the following is most likely to be a covalent compound?

A)KF
B)CaCl₂
C)SF₄
D)Al₂O₃
E)CaSO₄

Question 5

The Lewis dot symbol for the chloride ion is

A)
B) ^-
C) ^-
D) ^-
E)Cl^-

Question 6

Calculate the energy change for the reaction K(g)+ Br(g) $\rarr$ K⁺(g)+ Br^- (g)
Given the following ionization energy (IE)and electron affinity (EA)values

A)-1,092 kJ/mol
B)-95 kJ/mol
C)95 kJ/mol
D)1,092 kJ/mol
E)1,187 kJ/mol

Question 7

The Lewis dot symbol for the calcium ion is

A) ²⁺
B)(-Ca-)
C) ²⁺
D)Ca²⁺
E)Ca

Question 8

Which of the following pairs of elements would be most likely to form an ionic compound?

A)Cl and I
B)Al and K
C)Cl and Mg
D)C and S
E)Al and Mg

Question 9

Which of the following solids would have the highest melting point?

A)NaF
B)NaCl
C)NaBr
D)NaI

Question 10

Which one of the following is most likely to be an ionic compound?

A)NCl₃
B)BaCl₂
C)CO
D)SO₂
E)SF₄

Question 11

Which of the following ionic solids would have the largest lattice energy?

A)KF
B)KI
C)LiF
D)LiI
E)NaF

Question 12

Which one of the following ionic solids would have the largest lattice energy?

A)NaCl
B)NaF
C)CaBr₂
D)CsI
E)CaCl₂

Question 13

Which of the following ionic solids would have the largest lattice energy?

A)SrO
B)NaF
C)CaBr₂
D)CsI
E)BaSO₄

Question 14

Which of the following solids would have the highest melting point?

A)NaI
B)NaF
C)MgO
D)MgCl₂
E)KF

Question 15

The Lewis dot symbol for the a lead atom is

A)
B)
C)
D)
E)

Question 16

The Lewis dot symbol for the S ^2- ion is

A)
B) ^2-
C)(S^2-)
D)
-^2-
E) -

Question 17

Calculate the energy change for the reaction K(g)+ I(g) $\rarr$ K⁺(g)+ I ^- (g)
Given the following ionization energy (IE)and electron affinity (EA)values.

A)-124 kJ/mol
B)-715 kJ/mol
C)715 kJ/mol
D)1429 kJ/mol
E)None of these

Question 18

Complete this statement: Coulomb's law states that the magnitude of the force of interaction between two charged bodies is

A)directly proportional to the product of the charges on the bodies and directly proportional to the distance separating them.
B)directly proportional to the product of the charges on the bodies, and inversely proportional to the square of the distance separating them.
C)inversely proportional to the product of the charges on the bodies, and directly proportional to the square of the distance separating them.
D)directly proportional to the sum of the charges on the bodies, and inversely proportional to the square of the distance separating them.

Question 19

Which one of the following is most likely to be a covalent compound?

A)CsOH
B)NF₃
C)Sr(NO₃)₂
D)CaO
E)LiF

Question 20

Which one of the following is most likely to be an ionic compound?

A)CaCl₂
B)CO₂
C)CS₂
D)SO₂
E)OF₂

Question 21

Which of the elements listed below is the least electronegative?

A)Sr
B)V
C)Ni
D)P
E)I

Question 22

Which of the following covalent bonds is the most polar (i.e., highest percent ionic character)?

A)Al - I
B)Si - I
C)Al - Cl
D)Si - Cl
E)Si - P

Question 23

Use the Born-Haber cycle to calculate the lattice energy of KCl(s)given the following data: $\Delta$ H(sublimation)K = 79.2 kJ/mol
I₁ (K)= 418.7 kJ/mol
Bond energy (Cl-Cl)= 242.8 kJ/mol
EA (Cl)= 348 kJ/mol
$\Delta$ H (KCl(s))= -435.7 kJ/mol

A)-165 kJ/mol
B)288 kJ/mol
C)629 kJ/mol
D)707 kJ/mol
E)828 kJ/mol

Question 24

Which one of these polar covalent bonds would have the greatest percent ionic character?

A)H - Br
B)H - Cl
C)H - F
D)H - I

Question 25

A polar covalent bond would form in which one of the following pairs of atoms?

A)Cl - Cl
B)Si - Si
C)Ca - Cl
D)Cr - Br
E)P - Cl

Question 26

The covalent bond with the greatest polarity would form in which of the atom pairs below?

A)Br - Br
B)S - O
C)C - P
D)C - O
E)B - O

Question 27

Which of the elements listed below has the greatest electronegativity?

A)Se
B)Sb
C)K
D)Ga
E)Fe

Question 28

The bond in which of the following pairs of atoms would have the greatest percent ionic character (i.e., most polar)?

A)C - O
B)S - O
C)Na - I
D)Na - Br
E)F - F

Question 29

A nonpolar covalent bond (i.e., pure covalent)would form in which one of the following pairs of atoms?

A)Na - Cl
B)H - Cl
C)Li - Br
D)Se - Br
E)Br - Br

Question 30

Which of the elements listed below has the greatest electronegativity?

A)Na
B)As
C)Ga
D)Cs
E)Sb

Question 31

The bond in which of the following pairs of atoms would be the least polar (i.e., lowest percent ionic character)?

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

Question 32

Classify the C - Cl bond in CCl₄ as ionic, polar covalent, or nonpolar covalent.

A)ionic
B)polar covalent
C)nonpolar covalent

Question 33

The bond in which one of the following pairs of atoms would be the most polar?

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

Question 34

What type of chemical bond holds the atoms together within a water molecule?

A)Ionic bond
B)Nonpolar covalent bond
C)Polar covalent bond
D)Coordinate covalent bond

Question 35

Classify the O - H bond in CH₃OH as ionic, polar covalent, or nonpolar covalent.

A)ionic
B)polar covalent
C)nonpolar covalent

Question 36

Use the Born-Haber cycle to calculate the lattice energy of MgO (s)given the following data: $\Delta$ H(sublimation)Mg = 130 kJ/mol
I₁ (Mg)= 738.1 kJ/mol
I₂ (Mg)= 1450 kJ/mol
Bond energy (O=O)= 498.7 kJ/mol
EA (O)= 141 kJ/mol
EA (O^-)= -780 kJ/mol
$\Delta$ H (MgO(s))= -601.8 kJ/mol

A)2200 kJ/mol
B)2800 kJ/mol
C)3200 kJ/mol
D)3800 kJ/mol
E)4100 kJ/mol

Question 37

Use the Born-Haber cycle to calculate the standard enthalpy of formation ( $\Delta$ H )for LiCl(s)given the following data: $\Delta$ H(sublimation)Li = 155.2 kJ/mol
I₁ (Li)= 520 kJ/mol
Bond energy (Cl-Cl)= 242.7 kJ/mol
EA (Cl)= 349 kJ/mol
Lattice energy (LiCl(s))= 828 kJ/mol

A)440 kJ/mol
B)320 kJ/mol
C)-260 kJ/mol
D)-380 kJ/mol
E)-1420 kJ/mol

Question 38

Which of the atoms listed below is the most electronegative?

A)Li
B)Cs
C)P
D)As
E)Ge

Question 39

Which of the elements listed below has the greatest electronegativity?

A)Mg
B)Ga
C)Si
D)Ba
E)Pb

Question 40

Which of the bonds below would have the greatest polarity (i.e., highest percent ionic character)?

A)Si - P
B)Si - S
C)Si - Se
D)Si - Cl
E)Si - I

Question 41

Assuming the octet rule is obeyed, how many covalent bonds will a nitrogen atom form to give a formal charge of zero?

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

Question 42

The number of lone electron pairs in the CO₃^2- ion is ___.

A)4
B)5
C)6
D)7
E)8

Question 43

The Lewis structure for CS₂ is:

A)
B)
C)
D)

Question 44

The total number of bonding electrons in a molecule of formaldehyde (H₂CO)is

A)3.
B)4.
C)6.
D)8.
E)18.

Question 45

Assuming the octet rule is obeyed, how many covalent bonds will a carbon atom form to give a formal charge of zero?

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

Question 46

The number of lone electron pairs in the N₂ molecule is ___.

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

Question 47

Assuming the octet rule is obeyed, how many covalent bonds will a neon atom form to give a formal charge of zero?

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

Question 48

The formal charge on the bromine atom in BrO₃^- drawn with three single bonds is

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

Question 49

Classify the Ca - Cl bond in CaCl₂ as ionic, polar covalent, or nonpolar covalent.

A)ionic
B)polar covalent
C)nonpolar covalent

Question 50

The total number of lone pairs in NCl₃ is

A)6.
B)8.
C)9.
D)10.
E)13.

Question 51

Which of the following is a useful guideline for the application of formal charges in neutral molecules?

A)A Lewis structure in which there are no formal charges is preferred.
B)Lewis structures with large formal charges are preferred.
C)The preferred Lewis structure is one in which positive formal charges are on the most electronegative atoms.

Question 52

Which of the following Lewis structures is incorrect?

A)
B)
C)
D)
E)

Question 53

The electron dot formula for O₂ shows

A)a single covalent bond.
B)a double covalent bond.
C)an ionic bond.
D)a total of 8 x 2 = 16 electron dots.
E)a total of 32 electron dots.

Question 54

Assuming the octet rule is obeyed, how many covalent bonds will an oxygen atom form to give a formal charge of zero?

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

Question 55

The number of resonance structures for the sulfur dioxide molecule that satisfy the octet rule is

A)1.
B)2.
C)3.
D)4.
E)None of these.

Question 56

The number of lone electron pairs in the NO₂^- ion is ___.

A)4
B)5
C)6
D)7
E)8

Question 57

What is the formal charge on the oxygen atom in N₂O (the atomic order is N-N-O)?

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

Question 58

The azide ion, N₃^-, is very reactive although it is isoelectronic with the very stable CO₂ molecule. This reactivity is reasonable inasmuch as

A)a Lewis structure cannot be written for the azide ion that has nitrogen formal charges of zero.
B)there is no valid Lewis structure possible for the azide ion.
C)there are resonance structures for azide ion but not for carbon dioxide.
D)nitrogen cannot form multiple bonds.
E)charged species always decompose in solution.

Question 59

The electron dot structure for AsCl₃ shows

A)a total of 84 electron dots.
B)three single bonds and 10 lone pairs.
C)two single bonds, one double bond, and 9 lone pairs.
D)one single bond, two double bonds, and 8 lone pairs.
E)three single bonds and one lone pair.

Question 60

The number of resonance structures for the nitrate ion that satisfy the octet rule is

A)1.
B)2.
C)3.
D)4.
E)None of these.

Question 61

What is the formal charge on phosphorus in a Lewis structure for the phosphate ion that satisfies the octet rule?

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

Question 62

In the best Lewis structure for the fulminate ion, CNO^-, what is the formal charge on the central nitrogen atom?

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

Question 63

Which one of the following molecules has an atom with an expanded octet?

A)HCl
B)AsCl₅
C)ICl
D)NCl₃
E)Cl₂

Question 64

Which one of the following molecules has an atom with an incomplete octet?

A)NF₃
B)H₂O
C)AsCl₃
D)GeH₄
E)BF₃

Question 65

Which response includes all the molecules below that do not follow the octet rule? (1)H₂S (2)BCl₃ (3)PH₃ (4)SF₄

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

Question 66

What is total number of lone pairs in the best Lewis structure for SOF₄ that exceeds the octet rule (S is the central atom)?

A)0
B)2
C)14
D)16
E)18

Question 67

What is the formal charge on sulfur in the best Lewis structure for the SCN^- (thiocyanate)ion?

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

Question 68

Which of the elements listed below is most likely to exhibit an expanded octet in its compounds?

A)O
B)S
C)Na
D)C
E)N

Question 69

The formal charge on the sulfur atom in the resonance structure of sulfur dioxide which has one single bond and one double bond is

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

Question 70

Each of the three resonance structures of NO₃^- has how many lone pairs of electrons?

A)7
B)8
C)9
D)10
E)13

Question 71

Which one of the following compounds does not follow the octet rule?

A)NF₃
B)CO₂
C)CF₄
D)Br₂
E)NO

Question 72

For which of these species does the best Lewis structure have two or more equivalent resonance structures?

A)HCO₂^-
B)SCN^-
C)CNO^-
D)N₃^-
E)CO₂

Question 73

Which of the following substances will display an incomplete octet in its Lewis structure?

A)CO₂
B)Cl₂
C)ICl
D)NO
E)SO₂

Question 74

BeF₄^2- is called the fluoberyllate ion. The formal charge on the beryllium atom in this ion is

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

Question 75

Which one of the following compounds does not follow the octet rule?

A)NF₃
B)CF₄
C)PF₅
D)AsH₃
E)HCl

Question 76

In the Lewis structure of the iodate ion, IO₃^-, that satisfies the octet rule, the formal charge on the central iodine atom is

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

Question 77

How many covalent bonds will be drawn to bromine in BrO₃^- for the dot structure that expands the octet to minimize formal charge and if necessary places negative formal charges on the most electronegative atom(s)?

A)3
B)4
C)5
D)6
E)7

Question 78

What is the formal charge on the singly bonded oxygens in the Lewis structure for the carbonate ion?

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

Question 79

Nitrous oxide, N₂O, is sometimes called "laughing gas". What is the formal charge on the central nitrogen atom in the best Lewis structure for nitrous oxide? (The atom connectivity is N-N-O.)

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

Question 80

How many covalent bonds will be drawn to phosphorous in PO₄^3- for the dot structure that expands the octet to minimize formal charge and if necessary places negative formal charges on the most electronegative atom(s)?

A)4
B)5
C)6
D)7
E)8