Question 1

The melting points of metals are only moderately high because

Accepted Answer

A)  metallic bonding is weak. 
B)  metals have fewer bonding electrons than non-metals. 
C)  metals also have relatively low boiling points. 
D)  the melting process does not break the metallic bonds. 
E)  metals prefer to be bonded to non-metals. 
A)  metallic bonding is weak. 
B)  metals have fewer bonding electrons than non-metals. 
C)  metals also have relatively low boiling points. 
D)  the melting process does not break the metallic bonds. 
E)  metals prefer to be bonded to non-metals.

Question 2

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

Question 3

The majority of elements are good electrical conductors when in solid form.

Accepted Answer

A) True 
 B)False

Question 4

Which of the following contains covalent bonds?

Accepted Answer

A)  BaO 
B)  IBr 
C)  Mg 
D)  LiBr 
E)  Cu 
A)  BaO 
B)  IBr 
C)  Mg 
D)  LiBr 
E)  Cu

Question 5

The lattice energy of rubidium chloride is the energy change accompanying the process
Rb+(g) + Cl-(g) $\rightarrow$RbCl(s)
Calculate the lattice energy of RbCl using the following data:

Accepted Answer

Lattice en

Question 6

Which one of the following properties is least characteristic of substances composed of small, covalently-bonded molecules?

Accepted Answer

A)  low melting point 
B)  low boiling point 
C)  weak bonds 
D)  poor electrical conductor when solid 
E)  poor electrical conductor when molten 
A)  low melting point 
B)  low boiling point 
C)  weak bonds 
D)  poor electrical conductor when solid 
E)  poor electrical conductor when molten

Question 7

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

Accepted Answer

A) True 
 B)False

Question 8

Select the element whose Lewis symbol is correct.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 9

Covalently bonded substances do not necessarily exist as separate molecules.

Accepted Answer

A) True 
 B)False

Question 10

As a measure of the strength of metallic bonding, the boiling point of a metal is a better indicator than its melting point.

Accepted Answer

A) True 
 B)False

Question 11

Using appropriate, real examples to illustrate your answer, describe the correlation between bond energy and bond length for a series of varying bond order.

Accepted Answer

Carbon and oxygen form single, double an

Question 12

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

Question 13

Select the compound with the highest (i.e., most negative) lattice energy.

Accepted Answer

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

Question 14

Describe, with appropriate explanations, the key factors which affect the magnitude of the lattice energy of an ionic substance.

Accepted Answer

By Coulomb's law, the energy of two elec

Question 15

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

Question 16

Which of the following elements is the most electronegative?

Accepted Answer

A)  S 
B)  Ru 
C)  Si 
D)  Te 
E)  Cs 
A)  S 
B)  Ru 
C)  Si 
D)  Te 
E)  Cs

Question 17

The more C   O and O   H bonds there are in a substance, the greater will be the amount of heat released when a fixed mass of the substance is burned.

Accepted Answer

A) True 
 B)False

Question 18

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

Accepted Answer

A)  Mg(s) + Cl2(g) $\rightarrow$MgCl2(s) 
B)  Mg(g) + 2Cl(g) $\rightarrow$MgCl2(s) 
C)  Mg2+(s) + 2Cl¯(g) $\rightarrow$ MgCl2(g) 
D)  Mg2+(g) + 2Cl¯(g) $\rightarrow$ MgCl2(s) 
E)  MgCl2(aq) $\rightarrow$MgCl2(s) 
A)  Mg(s) + Cl2(g) $\rightarrow$MgCl2(s) 
B)  Mg(g) + 2Cl(g) $\rightarrow$MgCl2(s) 
C)  Mg2+(s) + 2Cl¯(g) $\rightarrow$ MgCl2(g) 
D)  Mg2+(g) + 2Cl¯(g) $\rightarrow$ MgCl2(s) 
E)  MgCl2(aq) $\rightarrow$MgCl2(s)

Question 19

A hypothetical ionic substance will not form merely because it has a high lattice energy. Explain why, using energy-based arguments.

Accepted Answer

In order for an ionic substance to form,

Question 20

Which of the following elements is the least electronegative?

Accepted Answer

A)  Si 
B)  Se 
C)  S 
D)  Sc 
E)  Sr 
A)  Si 
B)  Se 
C)  S 
D)  Sc 
E)  Sr

Exam 9: Models of Chemical Bonding

The melting points of metals are only moderately high because

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?

The majority of elements are good electrical conductors when in solid form.

Which of the following contains covalent bonds?

The lattice energy of rubidium chloride is the energy change accompanying the process Rb+(g) + Cl-(g) →\rightarrow→ RbCl(s) Calculate the lattice energy of RbCl using the following data:

Which one of the following properties is least characteristic of substances composed of small, covalently-bonded molecules?

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

Select the element whose Lewis symbol is correct.

Covalently bonded substances do not necessarily exist as separate molecules.

As a measure of the strength of metallic bonding, the boiling point of a metal is a better indicator than its melting point.

Using appropriate, real examples to illustrate your answer, describe the correlation between bond energy and bond length for a series of varying bond order.

Select the most polar bond amongst the following.

Select the compound with the highest (i.e., most negative) lattice energy.

Describe, with appropriate explanations, the key factors which affect the magnitude of the lattice energy of an ionic substance.

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 elements is the most electronegative?

The more C O and O H bonds there are in a substance, the greater will be the amount of heat released when a fixed mass of the substance is burned.

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

A hypothetical ionic substance will not form merely because it has a high lattice energy. Explain why, using energy-based arguments.

Which of the following elements is the least electronegative?

Keys to the Study of Chemistry

The Components of Matter

Stoichiometry of Formulas and Equations

Three Major Classes of Chemical Reactions

Gases and the Kinetic-Molecular Theory

Thermochemistry: Energy Flow and Chemical Change

Quantum Theory and Atomic Structure

Electron Configuration and Chemical Periodicity

The Shapes of Molecules

Theories of Covalent Bonding

Intermolecular Forces: Liquids, Solids, and Phase Changes

The Properties of Mixtures: Solutions and Colloids

Periodic Patterns in the Main-Group Elements

Organic Compounds and the Atomic Properties of Carbon

Kinetics: Rates and Mechanisms of Chemical Reactions

Equilibrium: the Extent of Chemical Reactions

Acid-Base Equilibria

Ionic Equilibria in Aqueous Systems

Thermodynamics: Entropy, Free Energy, and the Direction of Chemical Reactions

Electrochemistry: Chemical Change and Electrical Work

The Elements in Nature and Industry

The Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

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