Question 1

In which of the following processes does the enthalpy change (ΔH) directly represent the magnitude of the lattice energy of KCl(s)?

Accepted Answer

A)  Cl2(g) + 2K(s) → 2KC (s) 
B)  KCl(s) → K+(aq) + Cl- (aq) 
C)  KCl(s) → K+(g) + Cl-(g) 
D)  KCl(s) → K(s) + Cl-(g) 
E)  KCl(s) → K(s) + Cl(g)

Question 2

Electronegativities on Pauling's scale are calculated from ionization energies and electron affinities.

Accepted Answer

A) True 
 B)False

Question 3

Select the most polar bond amongst the following.

Accepted Answer

A)  C-O 
B)  Si-F 
C)  Cl-F 
D)  C-F 
E)  C-I

Question 4

Arrange aluminum, boron, nitrogen, and phosphorous in order of increasing electronegativity.

Accepted Answer

A)  Al<B<P<N 
B)  B<Al<N<P 
C)  Al<N<P<B 
D)  N<P<B<Al 
E)  None of these choices are correct.

Question 5

The electrostatic energy of two charged particles is inversely proportional to the distance between them.

Accepted Answer

A) True 
 B)False

Question 6

When two atoms form a covalently-bonded diatomic molecule, the distance between the nuclei at which the potential energy is at a minimum is called

Accepted Answer

A)  the bond energy. 
B)  the bond length. 
C)  the molecular diameter. 
D)  the covalent radius. 
E)  the covalent diameter.

Question 7

Which of the following is an ionic compound?

Accepted Answer

A)  H2S 
B)  NH3 
C)  I2 
D)  KI 
E)  CCl4

Question 8

Arrange oxygen, sulfur, calcium, rubidium, and potassium in order of decreasing electronegativity.

Accepted Answer

A)  O > S > Ca > K > Rb 
B)  O > S > Ca > Rb > K 
C)  O > S > Rb > K > Ca 
D)  O > S > Rb > Ca > K 
E)  None of these choices are correct.

Question 9

Based on electronegativity trends in the periodic table, predict which of the following compounds will have the greatest % ionic character in its bonds.

Accepted Answer

A)  H2O 
B)  LiI 
C)  CaO 
D)  RbF 
E)  HCl

Question 10

Analysis of an unknown substance showed that it has a high boiling point and is brittle. It is an insulator as a solid but conducts electricity when melted. Which of the following substances would have those characteristics?

Accepted Answer

A)  HCl 
B)  Al 
C)  KBr 
D)  SiF4 
E)  I2

Question 11

The electrostatic energy of two charged particles is inversely proportional to the square of the distance between them.

Accepted Answer

A) True 
 B)False

Question 12

Which one of the following properties is least characteristic of typical metals?

Accepted Answer

A)  moderately high melting point 
B)  high boiling point 
C)  brittleness 
D)  good electrical conductor when solid 
E)  good electrical conductor when molten

Question 13

Which of the following contains ionic bonding?

Accepted Answer

A)  CO 
B)  SrF2 
C)  Al 
D)  OCl2 
E)  HCl

Question 14

Analysis of an unknown substance showed that it has a moderate melting point and is a good conductor of heat and electricity in the solid phase. Which of the following substances would have those characteristics?

Accepted Answer

A)  NaCl 
B)  Si 
C)  CCl4 
D)  I2 
E)  Ga

Question 15

Select the compound with the highest lattice energy.

Accepted Answer

A)  CaS(s) 
B)  BaO(s) 
C)  NaI(s) 
D)  LiBr(s) 
E)  MgO(s)

Question 16

Quartz (SiO2) is a solid with a melting point of 1550 °C. The bonding in quartz is best described as

Accepted Answer

A)  lattice energy. 
B)  network attractions. 
C)  ionic bonding. 
D)  covalent bonding. 
E)  metallic bonding.

Question 17

The lattice energy of MgCl2 is the energy change for which one of the following processes?

Accepted Answer

A)  Mg(s) + Cl2(g) → MgCl2(s) 
B)  Mg(g) + 2Cl(g) → MgCl2(s) 
C)  Mg2+(s) + 2Cl-(g) → MgCl2(g) 
D)  Mg2+(g) + 2Cl-(g) → MgCl2(s) 
E)  MgCl2(aq) → MgCl2(s)

Question 18

No real bonds are 100% ionic in character.

Accepted Answer

A) True 
 B)False

Question 19

Which of the following is a covalent compound?

Accepted Answer

A)  Na2O 
B)  CaCl2 
C)  Cl2O 
D)  CsCl 
E)  Al2O3

Question 20

Covalently bonded substances do not necessarily exist as separate molecules.

Accepted Answer

A) True 
 B)False

Exam 9: Models of Chemical Bonding

In which of the following processes does the enthalpy change (ΔH) directly represent the magnitude of the lattice energy of KCl(s) ?

Electronegativities on Pauling's scale are calculated from ionization energies and electron affinities.

Select the most polar bond amongst the following.

Arrange aluminum, boron, nitrogen, and phosphorous in order of increasing electronegativity.

The electrostatic energy of two charged particles is inversely proportional to the distance between them.

When two atoms form a covalently-bonded diatomic molecule, the distance between the nuclei at which the potential energy is at a minimum is called

Which of the following is an ionic compound?

Arrange oxygen, sulfur, calcium, rubidium, and potassium in order of decreasing electronegativity.

Based on electronegativity trends in the periodic table, predict which of the following compounds will have the greatest % ionic character in its bonds.

Analysis of an unknown substance showed that it has a high boiling point and is brittle. It is an insulator as a solid but conducts electricity when melted. Which of the following substances would have those characteristics?

The electrostatic energy of two charged particles is inversely proportional to the square of the distance between them.

Which one of the following properties is least characteristic of typical metals?

Which of the following contains ionic bonding?

Analysis of an unknown substance showed that it has a moderate melting point and is a good conductor of heat and electricity in the solid phase. Which of the following substances would have those characteristics?

Select the compound with the highest lattice energy.

Quartz (SiO₂) is a solid with a melting point of 1550 °C. The bonding in quartz is best described as

The lattice energy of MgCl² is the energy change for which one of the following processes?

No real bonds are 100% ionic in character.

Which of the following is a covalent compound?

Covalently bonded substances do not necessarily exist as separate molecules.