Instructor Solutions Manual
Chemistry for Engineering Students
FOURTH EDITION
Lawrence s. Brown
Texas A&M University
Thomas A. Holme
Iowa State University
Prepared by
Steve Rathbone
Blinn College
Australia • Brazil • Mexico • Singapore • United Kingdom • United States
,Contents
Chapter 1
Introduction to Chemistry ................................................................................................................1
Chapter 2
Atoms and Molecules .....................................................................................................................20
Chapter 3
Molecules, Moles, and Chemical Equations ..................................................................................39
Chapter 4
Stoichiometry .................................................................................................................................71
Chapter 5
Gases ............................................................................................................................................106
Chapter 6
The Periodic Table and Atomic Structure ...................................................................................142
Chapter 7
Chemical Bonding and Molecular Structure ...............................................................................169
Chapter 8
Molecules and Materials..............................................................................................................195
Chapter 9
Energy and Chemistry..................................................................................................................219
Chapter 10
Entropy and the Second Law of Thermodynamics .......................................................................248
Chapter 11
Chemical Kinetics ........................................................................................................................283
Chapter 12
Chemical Equilibrium ..................................................................................................................321
Chapter 13
Electrochemistry ..........................................................................................................................365
Chapter 14
Nuclear Chemistry .......................................................................................................................396
ii
, Chapter 1
Introduction to Chemistry
Critical Materials
1.1 Are the elements designated as critical materials all rare?
Explain your answer.
They are not all necessarily rare, but many are found in only a few locations around the world
and as such are subject to supply disruptions.
1.2 In what country is most of the world’s cobalt mined? What events in that country
dramatically affected the price of cobalt?
The Democratic Republic of Congo produces most of the world’s cobalt. Political unrest in
that country once caused a 600% spike in the price of cobalt. Political instability continues
as well as issues with forced child labor in the mining of cobalt.
1.3 In what types of technology do the elements designated as critical materials generally play
important roles?
They are important in light emission, magnetism, and a variety of applications associated
with clean energy and electronics.
1.4 Based on the information in Figure 1.1, which three elements would you argue are the
most critical among the “critical materials”? Justify your answer.
Neodymium, dysprosium, and terbium. Neodymium and dysprosium have the highest
ranking in importance for clean energy. Dysprosium and terbium are ranked highest in
terms of potential supply risk.
1.5 In what region of the periodic table are most of the elements that are listed as critical
materials found?
Most of the critical elements are located in the middle of the periodic table, specifically the
region known as the lanthanide series and to a lesser extent the transition elements.
1.6 What agency of the U.S. government is responsible for identifying an element as a critical
material? What sorts of applications are the primary concern of this agency?
The Department of Energy (DOE) and an organization that it manages called the Critical
Materials Institute. Primary concerns are energy-related technologies, especially clean
energy applications such as wind and solar energy and electric cars.
1
© 2019 Cengage. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
, The Study of Chemistry
1.7 When making observations in the laboratory, which perspective of chemistry are we
normally using?
We make observations in the laboratory using the macroscopic perspective of chemistry,
unless very sophisticated instruments are used.
1.8 Which of the following items are matter and which are not? (a) a flashlight, (b) sunlight,
(c) an echo, (d) air at sea level, (e) air at the top of Mount Everest
(a) matter, (b) not matter, (c) not matter, (d) matter, (e) matter
1.9 Which macroscopic characteristics differentiate solids, liquids, and gases? (List as many as
possible.)
Solids maintain a definite shape; liquids and gases do not. Gases expand to completely
occupy their container; liquids assume the shape of the container but do not fully occupy it.
Solids tend to have high densities, liquids usually slightly lower, and gases typically have
very low densities, comparatively.
1.10 Do the terms element and atom mean the same thing? If not how do they differ?
No. An element is a pure substance, but the naturally occurring form of the element may
contain more than one atom. An example of this is elemental nitrogen (N2). In this case the
element has two atoms.
1.11 Label each of the following as either a physical process or a chemical process: (a) rusting
of an iron bridge, (b) melting of ice, (c) burning of a wooden stick, (d) digestion of a baked
potato, (e) dissolving of sugar in water.
A chemical change involves a change in the composition of matter; that is, some new
substances are formed. A physical change only involves a change in the physical state of
matter; no new substances are formed.
(a) rusting of an iron bridge Chemical, rust forms when iron and oxygen react
chemically.
(b) melting of ice Physical, change from the solid to the liquid
state.
(c) burning of a wooden stick Chemical, the molecules in the wood are changed
into carbon dioxide and water during combustion.
(d) digestion of a baked potato Chemical, larger food molecules are changed into
smaller ones and eventually oxidized (“burned”) to
produce energy.
(e) dissolving of sugar in water Physical, the sugar molecules are not changed they
just become surrounded by water molecules in
solution.
2
© 2019 Cengage. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
Chemistry for Engineering Students
FOURTH EDITION
Lawrence s. Brown
Texas A&M University
Thomas A. Holme
Iowa State University
Prepared by
Steve Rathbone
Blinn College
Australia • Brazil • Mexico • Singapore • United Kingdom • United States
,Contents
Chapter 1
Introduction to Chemistry ................................................................................................................1
Chapter 2
Atoms and Molecules .....................................................................................................................20
Chapter 3
Molecules, Moles, and Chemical Equations ..................................................................................39
Chapter 4
Stoichiometry .................................................................................................................................71
Chapter 5
Gases ............................................................................................................................................106
Chapter 6
The Periodic Table and Atomic Structure ...................................................................................142
Chapter 7
Chemical Bonding and Molecular Structure ...............................................................................169
Chapter 8
Molecules and Materials..............................................................................................................195
Chapter 9
Energy and Chemistry..................................................................................................................219
Chapter 10
Entropy and the Second Law of Thermodynamics .......................................................................248
Chapter 11
Chemical Kinetics ........................................................................................................................283
Chapter 12
Chemical Equilibrium ..................................................................................................................321
Chapter 13
Electrochemistry ..........................................................................................................................365
Chapter 14
Nuclear Chemistry .......................................................................................................................396
ii
, Chapter 1
Introduction to Chemistry
Critical Materials
1.1 Are the elements designated as critical materials all rare?
Explain your answer.
They are not all necessarily rare, but many are found in only a few locations around the world
and as such are subject to supply disruptions.
1.2 In what country is most of the world’s cobalt mined? What events in that country
dramatically affected the price of cobalt?
The Democratic Republic of Congo produces most of the world’s cobalt. Political unrest in
that country once caused a 600% spike in the price of cobalt. Political instability continues
as well as issues with forced child labor in the mining of cobalt.
1.3 In what types of technology do the elements designated as critical materials generally play
important roles?
They are important in light emission, magnetism, and a variety of applications associated
with clean energy and electronics.
1.4 Based on the information in Figure 1.1, which three elements would you argue are the
most critical among the “critical materials”? Justify your answer.
Neodymium, dysprosium, and terbium. Neodymium and dysprosium have the highest
ranking in importance for clean energy. Dysprosium and terbium are ranked highest in
terms of potential supply risk.
1.5 In what region of the periodic table are most of the elements that are listed as critical
materials found?
Most of the critical elements are located in the middle of the periodic table, specifically the
region known as the lanthanide series and to a lesser extent the transition elements.
1.6 What agency of the U.S. government is responsible for identifying an element as a critical
material? What sorts of applications are the primary concern of this agency?
The Department of Energy (DOE) and an organization that it manages called the Critical
Materials Institute. Primary concerns are energy-related technologies, especially clean
energy applications such as wind and solar energy and electric cars.
1
© 2019 Cengage. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
, The Study of Chemistry
1.7 When making observations in the laboratory, which perspective of chemistry are we
normally using?
We make observations in the laboratory using the macroscopic perspective of chemistry,
unless very sophisticated instruments are used.
1.8 Which of the following items are matter and which are not? (a) a flashlight, (b) sunlight,
(c) an echo, (d) air at sea level, (e) air at the top of Mount Everest
(a) matter, (b) not matter, (c) not matter, (d) matter, (e) matter
1.9 Which macroscopic characteristics differentiate solids, liquids, and gases? (List as many as
possible.)
Solids maintain a definite shape; liquids and gases do not. Gases expand to completely
occupy their container; liquids assume the shape of the container but do not fully occupy it.
Solids tend to have high densities, liquids usually slightly lower, and gases typically have
very low densities, comparatively.
1.10 Do the terms element and atom mean the same thing? If not how do they differ?
No. An element is a pure substance, but the naturally occurring form of the element may
contain more than one atom. An example of this is elemental nitrogen (N2). In this case the
element has two atoms.
1.11 Label each of the following as either a physical process or a chemical process: (a) rusting
of an iron bridge, (b) melting of ice, (c) burning of a wooden stick, (d) digestion of a baked
potato, (e) dissolving of sugar in water.
A chemical change involves a change in the composition of matter; that is, some new
substances are formed. A physical change only involves a change in the physical state of
matter; no new substances are formed.
(a) rusting of an iron bridge Chemical, rust forms when iron and oxygen react
chemically.
(b) melting of ice Physical, change from the solid to the liquid
state.
(c) burning of a wooden stick Chemical, the molecules in the wood are changed
into carbon dioxide and water during combustion.
(d) digestion of a baked potato Chemical, larger food molecules are changed into
smaller ones and eventually oxidized (“burned”) to
produce energy.
(e) dissolving of sugar in water Physical, the sugar molecules are not changed they
just become surrounded by water molecules in
solution.
2
© 2019 Cengage. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.
