Question 1

Which of the following period 3 chlorides would be expected to have the highest melting point?

Accepted Answer

A)  MgCl2 
B)  AlCl3 
C)  SiCl4 
D)  PCl3 
E)  SCl2 
A)  MgCl2 
B)  AlCl3 
C)  SiCl4 
D)  PCl3 
E)  SCl2 A

Question 2

Select the compound with the lowest (i.e., least negative) lattice energy.

Accepted Answer

A)  CsBr(s) 
B)  NaCl(s) 
C)  SrO(s) 
D)  CaO(s) 
E)  KBr(s) 
A)  CsBr(s) 
B)  NaCl(s) 
C)  SrO(s) 
D)  CaO(s) 
E)  KBr(s) A

Question 3

Select the correct formula for a compound formed from calcium and chlorine.

Accepted Answer

A)  CaCl 
B)  CaCl2 
C)  Ca2Cl 
D)  Ca2Cl2 
E)  CaCl3 
A)  CaCl 
B)  CaCl2 
C)  Ca2Cl 
D)  Ca2Cl2 
E)  CaCl3 B

Question 4

The melting points of metals are only moderately high because

Accepted Answer

A)  metallic bonding is weak. 
B)  metals have fewer bonding electrons than nonmetals. 
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 nonmetals. 
A)  metallic bonding is weak. 
B)  metals have fewer bonding electrons than nonmetals. 
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 nonmetals.

Question 5

In which of these substances are the atoms held together by metallic bonding?

Accepted Answer

A)  CO2 
B)  Si 
C)  Br2 
D)  S8 
E)  Cr 
A)  CO2 
B)  Si 
C)  Br2 
D)  S8 
E)  Cr

Question 6

Nitrogen and hydrogen combine to form ammonia in the Haber process. Calculate (in kJ) the standard enthalpy change ΔH° for the reaction written below, using the bond energies given. N2(g) + 3H2(g) → 2NH3(g)
Bond: N≡N H-H N-H
Bond energy(kJ/mol): 945 432 391

Accepted Answer

A)  -969 kJ 
B)  -204 kJ 
C)  -105 kJ 
D)  204 kJ 
E)  595 kJ 
A)  -969 kJ 
B)  -204 kJ 
C)  -105 kJ 
D)  204 kJ 
E)  595 kJ

Question 7

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 8

Which of the following elements is the most electronegative?

Accepted Answer

A)  Ne 
B)  Rb 
C)  P 
D)  I 
E)  Cl 
A)  Ne 
B)  Rb 
C)  P 
D)  I 
E)  Cl

Question 9

Select the correct formula for a compound formed from barium and nitrogen.

Accepted Answer

A)  BaN 
B)  BaN2 
C)  Ba2N3 
D)  Ba2N 
E)  Ba3N2 
A)  BaN 
B)  BaN2 
C)  Ba2N3 
D)  Ba2N 
E)  Ba3N2

Question 10

For which of the following elements (in their normal, stable, forms) would it be correct to describe the bonding as involving "electron pooling"?

Accepted Answer

A)  hydrogen 
B)  helium 
C)  sulfur 
D)  iodine 
E)  aluminum 
A)  hydrogen 
B)  helium 
C)  sulfur 
D)  iodine 
E)  aluminum

Question 11

The lattice energy for ionic crystals increases as the charge on the ions _____________ and the size of the ions __________________.

Accepted Answer

A)  increases; increases 
B)  increases; decreases 
C)  decreases; increases 
D)  decreases; decreases 
E)  None of these choices are correct. 
A)  increases; increases 
B)  increases; decreases 
C)  decreases; increases 
D)  decreases; decreases 
E)  None of these choices are correct.

Question 12

The lattice energy of large ions is greater in magnitude than that of small ions of the same charge.

Accepted Answer

A) True 
 B)False

Question 13

In covalent bond formation, the potential energy reaches a maximum when the internuclear distance is equal to the bond length.

Accepted Answer

A) True 
 B)False

Question 14

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

Question 15

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

Accepted Answer

A) True 
 B)False

Question 16

Acetone can be easily converted to isopropyl alcohol by addition of hydrogen to the carbon-oxygen double bond. Calculate the enthalpy of reaction using the bond energies given.

Accepted Answer

A)  -484 kJ 
B)  -366 kJ 
C)  -61 kJ 
D)  +61 kJ 
E)  +366 kJ 
A)  -484 kJ 
B)  -366 kJ 
C)  -61 kJ 
D)  +61 kJ 
E)  +366 kJ

Question 17

Arrange the following bonds in order of increasing bond strength.

Accepted Answer

A)  C-I < C-Br < C-Cl < C-F 
B)  C-F < C-Cl < C-Br < C-I 
C)  C-Br < C-I < C-Cl < C-F 
D)  C-I < C-Br < C-F< C-Cl 
E)  None of these choices are correct. 
A)  C-I < C-Br < C-Cl < C-F 
B)  C-F < C-Cl < C-Br < C-I 
C)  C-Br < C-I < C-Cl < C-F 
D)  C-I < C-Br < C-F< C-Cl 
E)  None of these choices are correct.

Question 18

Which one of the following properties is least characteristic of typical ionic compounds?

Accepted Answer

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

Question 19

Select the element whose Lewis symbol is correct.

Accepted Answer

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

Question 20

Calculate the lattice energy of magnesium sulfide from the data given below. Mg(s) → Mg(g) ΔH° = 148 kJ/mol
Mg(g) → Mg2+(g) + 2e- ΔH° = 2186 kJ/mol
S8(s) → 8S(g) ΔH° = 2232 kJ/mol
S(g) + 2e- → S2-(g) ΔH° = 450 kJ/mol
8Mg(s) + S8(s) → 8MgS(s) ΔH° = -2744 kJ/mol
Mg2+(g) + S2-(g) → MgS(s) ΔH°lattice = ?

Accepted Answer

A)  -3406 kJ/mol 
B)  -2720. kJ/mol 
C)  2720. kJ/mol 
D)  3406 kJ/mol 
E)  None of these choices are correct. 
A)  -3406 kJ/mol 
B)  -2720. kJ/mol 
C)  2720. kJ/mol 
D)  3406 kJ/mol 
E)  None of these choices are correct.

Exam 9: Models of Chemical Bonding

Which of the following period 3 chlorides would be expected to have the highest melting point?

Select the compound with the lowest (i.e., least negative) lattice energy.

Select the correct formula for a compound formed from calcium and chlorine.

The melting points of metals are only moderately high because

In which of these substances are the atoms held together by metallic bonding?

Nitrogen and hydrogen combine to form ammonia in the Haber process. Calculate (in kJ) the standard enthalpy change ΔH° for the reaction written below, using the bond energies given. N2(g) + 3H2(g) → 2NH3(g) Bond: N≡N H-H N-H Bond energy(kJ/mol): 945 432 391

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.

Which of the following elements is the most electronegative?

Select the correct formula for a compound formed from barium and nitrogen.

For which of the following elements (in their normal, stable, forms) would it be correct to describe the bonding as involving "electron pooling"?

The lattice energy for ionic crystals increases as the charge on the ions _____________ and the size of the ions __________________.

The lattice energy of large ions is greater in magnitude than that of small ions of the same charge.

In covalent bond formation, the potential energy reaches a maximum when the internuclear distance is equal to the bond length.

Which of the following elements is the least electronegative?

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

Acetone can be easily converted to isopropyl alcohol by addition of hydrogen to the carbon-oxygen double bond. Calculate the enthalpy of reaction using the bond energies given.

Arrange the following bonds in order of increasing bond strength.

Which one of the following properties is least characteristic of typical ionic compounds?

Select the element whose Lewis symbol is correct.

Keys to Studying Chemistry Definitions, Units, and Problem Solving

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 Reaction Direction

Electrochemistry Chemical Change and Electrical Work

The Elements in Nature and Industry

Transition Elements and Their Coordination Compounds

Nuclear Reactions and Their Applications

Filters

Nitrogen and hydrogen combine to form ammonia in the Haber process. Calculate (in kJ) the standard enthalpy change ΔH° for the reaction written below, using the bond energies given. N₂(g) + 3H₂(g) → 2NH₃(g) Bond: N≡N H-H N-H Bond energy(kJ/mol): 945 432 391

The lattice energy for ionic crystals increases as the charge on the ions _ and the size of the ions ______.