Principles of chemistry 3e by nivaldo j tro 1

Main groups

1
2
3
4
5
6
7

1Aa
1
1
H
1.008

2A
2

3
Li

4
Be

6.94

9.012

11

Na

12
Mg

22.99

24.31

19
K

Main groups

Metals

Metalloids

Transition metals
8
26
Fe

8B
9
27
Co

54.94

55.85

58.93

43
Tc

44
Ru

45
Rh

[98]

101.07

102.91

20
Ca

3B
3
21
Sc

4B
4
22

Ti

5B
5
23
V

6B
6
24
Cr

7B
7
25
Mn

39.10

40.08

44.96

47.87

50.94

52.00

37

Rb

38
Sr

39
Y

40
Zr

41
Nb

42
Mo

85.47

87.62

88.91

92.91

95.95

56
Ba

57
La

91.22

55
Cs
132.91

137.33

138.91

178.49

180.95

183.84

186.21

190.23

87
Fr

88
Ra

89

Ac

104
Rf

105
Db

106
Sg

107
Bh

[223.02]

[226.03]

[227.03]

[261.11]

[262.11]

[266.12]

58
Ce

72

Hf

Lanthanide series
Actinide series

5A
15
7
N

6A
16

7A
17

4.003

5
B

4A
14
6
C

8
O

9

F

10
Ne

10.81

12.01

14.01

16.00

19.00

20.18

13
Al

14
Si

15
P

16
S

17

Cl

18
Ar

26.98

28.09

30.97

32.06

35.45

39.95

3A
13

Nonmetals

8A
18
2
He

10
28
Ni

1B
11
29
Cu

2B
12
30
Zn

58.69

63.55

65.38

69.72

72.63

74.92

78.97

79.90

83.80

106.42

107.87

112.41

114.82

118.71

121.76

127.60

126.90

131.29

78
Pt

79
Au

80
Hg

81
Tl

82

Pb

83
Bi

84
Po

85
At

86
Rn

192.22

195.08

196.97

200.59

204.38

207.2

208.98

[208.98]

[209.99]

[222.02]

108
Hs

109
Mt

110
Ds

111
Rg

112
Cn

113

114
Fl

115

116
Lv

117*

118

[264.12]

[269.13]

[268.14]

[271]

[272]

[285]

59
Pr

60
Nd

61
Pm

62
Sm

63
Eu

64
Gd

65
Tb

66
Dy

67
Ho

68
Er

69
Tm

70
Yb

71
Lu

140.12

140.91

144.24

[145]

150.36

151.96

157.25

158.93

162.50

164.93

167.26

168.93

173.05

174.97

90
Th

91
Pa

92
U

93
Np

94
Pu

95
Am

96
Cm

97
Bk

98
Cf

99
Es

100
Fm

101
Md

102
No

103
Lr

232.04

231.04

238.03

[237.05]

[244.06]

[243.06]

[247.07]

[247.07]

[251.08]

[252.08]

[257.10]

[258.10]

[259.10]

[262.11]

73
Ta

74
W

75
Re

76
Os

77
Ir

46
Pd

47
Ag

48
Cd

31
Ga

32

Ge

49
In

50
Sn

33
As
51
Sb

by the International Union of Pure and Applied Chemistry.
Atomic masses in brackets are the masses of the longest-lived or most important isotope of radioactive elements.
*Element 117 is currently under review by IUPAC.

52
Te

35
Br
53
I

36
Kr

54
Xe

[292]

[289]

a The labels on top (1A, 2A, etc.) are common American usage. The labels below these (1, 2, etc.) are those recommended

34
Se


List of Elements with Their Symbols and Atomic Masses
Element
Actinium
Aluminum
Americium
Antimony
Argon
Arsenic
Astatine
Barium
Berkelium
Beryllium
Bismuth
Bohrium
Boron
Bromine
Cadmium
Calcium
Californium

Carbon
Cerium
Cesium
Chlorine
Chromium
Cobalt
Copernicium
Copper
Curium
Darmstadtium
Dubnium
Dysprosium
Einsteinium
Erbium
Europium
Fermium
Flerovium
Fluorine
Francium
Gadolinium
Gallium
Germanium
Gold
Hafnium
Hassium
Helium
Holmium
Hydrogen
Indium
Iodine

Iridium
Iron
Krypton
Lanthanum
Lawrencium
Lead
Lithium
Livermorium
Lutetium
Magnesium
Manganese

Symbol
Ac
Al
Am
Sb
Ar
As
At
Ba
Bk
Be
Bi
Bh
B
Br
Cd
Ca
Cf

C
Ce
Cs
Cl
Cr
Co
Cn
Cu
Cm
Ds
Db
Dy
Es
Er
Eu
Fm
Fl
F
Fr
Gd
Ga
Ge
Au
Hf
Hs
He
Ho
H
In
I

Ir
Fe
Kr
La
Lr
Pb
Li
Lv
Lu
Mg
Mn

Atomic
Number
89
13
95
51
18
33
85
56
97
4
83
107
5
35
48
20

98
6
58
55
17
24
27
112
29
96
110
105
66
99
68
63
100
114
9
87
64
31
32
79
72
108
2
67
1
49

53
77
26
36
57
103
82
3
116
71
12
25

a

Mass of longest-lived or most important isotope.

b

The names of these elements have not yet been decided.

Atomic Mass
a

227.03
26.98
243.06a
121.76
39.95
74.92

209.99a
137.33
247.07a
9.012
208.98
264.12a
10.81
79.90
112.41
40.08
251.08a
12.01
140.12
132.91
35.45
52.00
58.93
285a
63.55
247.07a
271a
262.11a
162.50
252.08a
167.26
151.96
257.10a
289a
19.00
223.02a

157.25
69.72
72.63
196.97
178.49
269.13a
4.003
164.93
1.008
114.82
126.90
192.22
55.85
83.80
138.91
262.11a
207.2
6.94
292a
174.97
24.31
54.94

Element
Meitnerium
Mendelevium
Mercury
Molybdenum
Neodymium
Neon

Neptunium
Nickel
Niobium
Nitrogen
Nobelium
Osmium
Oxygen
Palladium
Phosphorus
Platinum
Plutonium
Polonium
Potassium
Praseodymium
Promethium
Protactinium
Radium
Radon
Rhenium
Rhodium
Roentgenium
Rubidium
Ruthenium
Rutherfordium
Samarium
Scandium
Seaborgium
Selenium
Silicon
Silver

Sodium
Strontium
Sulfur
Tantalum
Technetium
Tellurium
Terbium
Thallium
Thorium
Thulium
Tin
Titanium
Tungsten
Uranium
Vanadium
Xenon
Ytterbium
Yttrium
Zinc
Zirconium
*b
*b

Symbol

Atomic
Number

Atomic Mass

Mt
Md
Hg
Mo
Nd
Ne
Np
Ni
Nb
N
No
Os
O
Pd
P
Pt
Pu
Po
K
Pr
Pm
Pa
Ra
Rn
Re
Rh
Rg
Rb
Ru
Rf

Sm
Sc
Sg
Se
Si
Ag
Na
Sr
S
Ta
Tc
Te
Tb
Tl
Th
Tm
Sn
Ti
W
U
V
Xe
Yb
Y
Zn
Zr

109
101
80

42
60
10
93
28
41
7
102
76
8
46
15
78
94
84
19
59
61
91
88
86
75
45
111
37
44
104
62
21
106

34
14
47
11
38
16
73
43
52
65
81
90
69
50
22
74
92
23
54
70
39
30
40

268.14a
258.10a
200.59
95.95
144.24
20.18

237.05a
58.69
92.91
14.01
259.10a
190.23
16.00
106.42
30.97
195.08
244.06a
208.98a
39.10
140.91
145a
231.04
226.03a
222.02a
186.21
102.91
272a
85.47
101.07
261.11a
150.36
44.96
266.12a
78.97
28.09
107.87

22.99
87.62
32.06
180.95
98a
127.60
158.93
204.38
232.04
168.93
118.71
47.87
183.84
238.03
50.94
131.293
173.05
88.91
65.38
91.22

113
115

284a
288a


Principles of Chemistry
A Molecular Approach

Third ediTion

NivAldo J. Tro
Westmont College


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Library of Congress Cataloging-in-Publication Data
Tro, Nivaldo J.
Principles of Chemistry : a molecular approach / Nivaldo J. Tro, WestmontCollege. -- Third edition.
p cm
ISBN 978-0-321-97194-4
1. Chemistry, Physical and theoretical--Textbooks. 2. Chemistry, Physical and theoretical--Study and
teaching (Higher) I. Title.
QD453.3.T76 2016
540--dc23
2014040200
1 2 3 4 5 6 7 8 9 10—V011—16 15 14 13 12
ISBN 10: 0-321-97194-9; ISBN 13: 978-0-32197194-4

www.pearsonhighered.com


To Michael, Ali, Kyle, and Kaden

About the Author
Nivaldo Tro is a professor of chemistry at Westmont College
in Santa Barbara, California, where he has been a faculty

member since 1990. He received his Ph.D. in chemistry from
Stanford University for work on developing and using optical
techniques to study the adsorption and desorption of molecules to and from surfaces in ultrahigh vacuum. He then went
on to the University of California at Berkeley, where he did
postdoctoral research on ultrafast reaction dynamics in solution. Since coming to Westmont, Professor Tro has been
awarded grants from the American Chemical Society
Petroleum Research Fund, from the Research Corporation, and from the National Science Foundation to study
the dynamics of various processes occurring in thin adlayer films adsorbed on dielectric surfaces. He has been
honored as Westmont’s outstanding teacher of the year three times and has also received the college’s outstanding researcher of the year award. Professor Tro lives in Santa Barbara with his wife, Ann, and their four
children, Michael, Ali, Kyle, and Kaden. In his leisure time, Professor Tro enjoys mountain biking, surfing,
reading to his children, and being outdoors with his family.

iii


Brief Contents
Preface
1 Matter, Measurement, and Problem Solving

xv
2

2 Atoms and Elements

42

3 Molecules, Compounds, and Chemical Equations

76

4 Chemical Quantities and Aqueous Reactions

124

5 Gases

176

6 Thermochemistry

220

7 The Quantum-Mechanical Model of the Atom

262

8 Periodic Properties of the Elements

300

9 Chemical Bonding I: The Lewis Model

340

10 Chemical Bonding II: Molecular Shapes, Valence Bond Theory, and

Molecular Orbital Theory
11 Liquids, Solids, and Intermolecular Forces

428

Solutions
Chemical Kinetics
Chemical Equilibrium
Acids and Bases
Aqueous Ionic Equilibrium
Free Energy and Thermodynamics
Electrochemistry
Radioactivity and Nuclear Chemistry

478

776

Appendix I: Common Mathematical Operations in Chemistry

A-1

Appendix II: Useful Data

A-7

12
13
14
15
16
17
18
19

iv

378

518
562
602
646
692
734

Appendix III: Answers to Selected Exercises

A-17

Appendix IV: Answers to In-Chapter Practice Problems

A-42

Glossary

G-1

Credits

C-1

Index

i-1


Contents
Preface

xv

1 Matter, Measurement,
and Problem Solving

2

1.1 Atoms and Molecules
1.2 The Scientific Approach to Knowledge
1.3 The Classification of Matter

3
5
7

The States of Matter: Solid, Liquid, and Gas 7 Classifying
Matter According to Its Composition: Elements, Compounds,
and Mixtures 8

1.4 Physical and Chemical Changes and
Physical and Chemical Properties
1.5 Energy: A Fundamental Part of Physical and
Chemical Change
1.6 The Units of Measurement

9
12
13

The Standard Units 13 The Meter: A Measure of Length 14
The Kilogram: A Measure of Mass 14 The Second: A
Measure of Time 14 The Kelvin: A Measure of
Temperature 14 Prefix Multipliers 16 Derived Units: Volume
and Density 17 Volume 17 Density 18 Calculating
Density 18

1.7 The reliability of a Measurement

19

Counting Significant Figures 21 Exact Numbers 22
Significant Figures in Calculations 23 Precision and
Accuracy 24

1.8 Solving Chemical Problems

25

Converting from One Unit to Another 25 General ProblemSolving Strategy 27 Units Raised to a Power 29
Problems Involving an Equation 30

Chapter in review

33

Key Terms 33 Key Concepts 33 Key Equations and
Relationships 34 Key Learning Objectives 34

Exercises
Problems by Topic 34 Cumulative Problems 38
Challenge Problems 39 Conceptual Problems 40
Questions for Group Work 41 Answers to Conceptual
Connections 41

34

2 Atoms and Elements
2.1 imaging and Moving individual Atoms
2.2 Modern Atomic Theory and the laws
That led to it

42
43
45

The Law of Conservation of Mass 45 The Law of Definite
Proportions 46 The Law of Multiple Proportions 47 John
Dalton and the Atomic Theory 48

2.3 The discovery of the Electron

48

Cathode Rays 49 Millikan’s Oil Drop Experiment:

The Charge of the Electron 50

2.4 The Structure of the Atom
2.5 Subatomic Particles: Protons, Neutrons, and
Electrons in Atoms

50
52

Elements: Defined by Their Numbers of Protons 53
Isotopes: When the Number of Neutrons Varies 54
Ions: Losing and Gaining Electrons 56

2.6 Finding Patterns: The Periodic law and
the Periodic Table

57

Ions and the Periodic Table 59

2.7 Atomic Mass: The Average Mass of an
Element’s Atoms
2.8 Molar Mass: Counting Atoms by Weighing Them

61
62

The Mole: A Chemist’s “Dozen” 62 Converting between
Number of Moles and Number of Atoms 63 Converting
between Mass and Amount (Number of Moles) 64

Chapter in review

68

Key Terms 68 Key Concepts 69 Key Equations and
Relationships 69 Key Learning Objectives 69

Exercises

70

Problems by Topic 70 Cumulative Problems 72
Challenge Problems 73 Conceptual Problems 74
Questions for Group Work 74 Answers to Conceptual
Connections 75

v


vi

Contents

3 Molecules, Compounds, and
Chemical Equations

76

3.1 Hydrogen, oxygen, and Water

3.2 Chemical Bonds

77
79

Ionic Bonds 79 Covalent Bonds 80

3.3 representing Compounds: Chemical Formulas
and Molecular Models

80

Types of Chemical Formulas 80 Molecular Models 82

3.4 An Atomic-level view of Elements and Compounds
3.5 ionic Compounds: Formulas and Names

82
86

Writing Formulas for Ionic Compounds 87 Naming Ionic
Compounds 87 Naming Binary Ionic Compounds
Containing a Metal That Forms Only One Type of Cation 89
Naming Binary Ionic Compounds Containing a Metal That
Forms More Than One Kind of Cation 90 Naming Ionic
Compounds Containing Polyatomic Ions 91 Hydrated Ionic
Compounds 92

3.6 Molecular Compounds: Formulas and Names

93

Naming Molecular Compounds 93 Naming Acids 94
Naming Binary Acids 95 Naming Oxyacids 95
96

Molar Mass of a Compound 97 Using Molar Mass
to Count Molecules by Weighing 97

3.8 Composition of Compounds

99

Conversion Factors from Chemical Formulas 101
102

Chapter in review

107
111
114

Key Terms 114 Key Concepts 114 Key Equations
and Relationships 115 Key Learning Objectives 116

Exercises

4.1 Climate Change and the Combustion of Fossil Fuels 125
4.2 reaction Stoichiometry: How Much
Carbon dioxide?

127

4.3 limiting reactant, Theoretical Yield, and
Percent Yield

131

Limiting Reactant, Theoretical Yield, and Percent Yield
from Initial Reactant Masses 133
Solution Concentration 138 Using Molarity in
Calculations 139 Solution Stoichiometry 143

4.5 Types of Aqueous Solutions and Solubility

Writing Balanced Chemical Equations 109

3.11 organic Compounds

124

4.4 Solution Concentration and Solution Stoichiometry 137

Calculating Molecular Formulas for
Compounds 104 Combustion Analysis 105

3.10 Writing and Balancing Chemical Equations

Aqueous reactions

Making Pizza: The Relationships Among Ingredients 127

Making Molecules: Mole-to-Mole Conversions 128
Making Molecules: Mass-to-Mass Conversions 128

3.7 Formula Mass and the Mole Concept
for Compounds

3.9 determining a Chemical Formula from
Experimental data

4 Chemical Quantities and

144

Electrolyte and Nonelectrolyte Solutions 145 The Solubility
of Ionic Compounds 146

4.6 Precipitation reactions
148
4.7 representing Aqueous reactions: Molecular, ionic,
and Complete ionic Equations
152
4.8 Acid–Base and Gas-Evolution reactions
154
Acid–Base Reactions 154 Gas-Evolution Reactions 157

117

Problems by Topic 117 Cumulative Problems 120
Challenge Problems 121 Conceptual Problems 122
Questions for Group Work 122 Answers to Conceptual

Connections 122

4.9 oxidation–reduction reactions

159

Oxidation States 161 Identifying Redox Reactions 163
Combustion Reactions 165

Chapter in review

167

Key Terms 167 Key Concepts 167 Key Equations and
Relationships 168 Key Learning Objectives 168

Exercises

168

Problems by Topic 168 Cumulative Problems 172
Challenge Problems 173 Conceptual Problems 174
Questions for Group Work 175 Answers to Conceptual
Connections 175

5 Gases
5.1 Breathing: Putting Pressure to Work
5.2 Pressure: The result of Molecular Collisions
Pressure Units 179

176
177
178


vii

Contents

6.4 Quantifying Heat and Work

230

Heat 230 Thermal Energy Transfer 232 Work:
Pressure–Volume Work 234

6.5 Measuring 𝚫E for Chemical reactions: Constantvolume Calorimetry
235
6.6 Enthalpy: The Heat Evolved in a Chemical reaction at
Constant Pressure
238
Exothermic and Endothermic Processes: A Molecular
View 240 Stoichiometry Involving ∆H: Thermochemical
Equations 241

5.3 The Simple Gas laws: Boyle’s law, Charles’s law,
and Avogadro’s law

180

Boyle’s Law: Volume and Pressure 181 Charles’s Law:
Volume and Temperature 183 Avogadro’s Law: Volume and
Amount (in Moles) 185

5.4 The ideal Gas law
5.5 Applications of the ideal Gas law: Molar volume,
density, and Molar Mass of a Gas

186
188

Molar Volume at Standard Temperature and Pressure 189
Density of a Gas 189 Molar Mass of a Gas 191

5.6 Mixtures of Gases and Partial Pressures

192

Collecting Gases over Water 196

5.7 Gases in Chemical reactions: Stoichiometry
revisited

6.7 Constant-Pressure Calorimetry: Measuring 𝚫Hrxn
6.8 Hess’s law and other relationships
involving 𝚫Hrxn
6.9 Enthalpies of reaction from Standard
Heats of Formation

242

244
247

Standard States and Standard Enthalpy Changes 247
Calculating the Standard Enthalpy Change for a Reaction 249

Chapter in review

253

Key Terms 253 Key Concepts 253 Key Equations and
Relationships 254 Key Learning Objectives 254

Exercises

255

Problems by Topic 255 Cumulative Problems 258
Challenge Problems 259 Conceptual Problems 260
Questions for Group Work 260 Answers to Conceptual
Connections 261

198

Molar Volume and Stoichiometry 200

5.8 Kinetic Molecular Theory: A Model for Gases

201

The Nature of Pressure 202 Boyle’s Law 202 Charles’s
Law 202 Avogadro’s Law 202 Dalton’s Law 202
Temperature and Molecular Velocities 203

5.9 Mean Free Path, diffusion, and
Effusion of Gases
205
5.10 real Gases: The Effects of Size and intermolecular
Forces
207
The Effect of the Finite Volume of Gas Particles 207 The Effect
of Intermolecular Forces 208 Van der Waals Equation 209

Chapter in review

210

Key Terms 210 Key Concepts 210 Key Equations and
Relationships 211 Key Learning Objectives 211

Exercises

212

Problems by Topic 212 Cumulative Problems 215
Challenge Problems 217 Conceptual Problems 218
Questions for Group Work 218 Answers to Conceptual
Connections 219

6 Thermochemistry

6.1 Chemical Hand Warmers
6.2 The Nature of Energy: Key definitions

220
221
222

Units of Energy 224

6.3 The First law of Thermodynamics: There is
No Free lunch
Internal Energy 225

225

7 The Quantum-Mechanical Model
of the Atom

7.1 Schrödinger’s Cat
7.2 The Nature of light

262
264
264

The Wave Nature of Light 265 The Electromagnetic
Spectrum 267 Interference and Diffraction 268 The
Particle Nature of Light 270

7.3 Atomic Spectroscopy and the Bohr Model

273
7.4 The Wave Nature of Matter: The de Broglie Wavelength,
the Uncertainty Principle, and indeterminacy
275
The de Broglie Wavelength 276 The Uncertainty
Principle 277 Indeterminacy and Probability Distribution
Maps 279


viii

Contents

Trends in First Ionization Energy 325 Exceptions to Trends in
First Ionization Energy 328 Trends in Second and
Successive Ionization Energies 328

8.8 Electron Affinities and Metallic Character

329

Electron Affinity 329 Metallic Character 330

Chapter in review

334

Key Terms 334 Key Concepts 334 Key Equations and
Relationships 335 Key Learning Objectives 335

Exercises

335

Problems by Topic 335 Cumulative Problems 337
Challenge Problems 338 Conceptual Problems 338
Questions for Group Work 339 Answers to Conceptual
Connections 339

7.5 Quantum Mechanics and the Atom

281

Solutions to the Schrödinger Equation for the Hydrogen
Atom 281 Atomic Spectroscopy Explained 285

7.6 The Shapes of Atomic orbitals

287

s Orbitals (l=0) 288 p Orbitals (l=1) 290 d Orbitals
(l=2) 291 f Orbitals (l=3) 292 The Phase of
Orbitals 292 The Shapes of Atoms 292

Chapter in review

293

Key Terms 293 Key Concepts 294 Key Equations and
Relationships 294 Key Learning Objectives 295

Exercises

295

Problems by Topic 295 Cumulative Problems 296
Challenge Problems 297 Conceptual Problems 298
Questions for Group Work 298 Answers to Conceptual
Connections 298

9 Chemical Bonding i:
The lewis Model

8 Periodic Properties of
the Elements

8.1 Nerve Signal Transmission
8.2 The development of the Periodic Table
8.3 Electron Configurations: How Electrons
occupy orbitals

300
301
302
303

Electron Spin and the Pauli Exclusion Principle 304
Sublevel Energy Splitting in Multielectron Atoms 304
Electron Spatial Distributions and Sublevel Splitting 306
Electron Configurations for Multielectron Atoms 308

8.4 Electron Configurations, valence Electrons, and the
Periodic Table
311
Orbital Blocks in the Periodic Table 312 Writing an
Electron Configuration for an Element from Its Position in
the Periodic Table 313 The Transition and Inner Transition
Elements 314

8.5 The Explanatory Power of the Quantum-Mechanical
Model
315
8.6 Periodic Trends in the Size of Atoms and Effective
Nuclear Charge
316
Effective Nuclear Charge 318 Atomic Radii and the
Transition Elements 319

8.7 ions: Electron Configurations, Magnetic Properties,
ionic radii, and ionization Energy
321
Electron Configurations and Magnetic Properties of
Ions 321 Ionic Radii 322 Ionization Energy 325

9.1
9.2
9.3
9.4

Bonding Models and AidS drugs

Types of Chemical Bonds
representing valence Electrons with dots
ionic Bonding: lewis Symbols and
lattice Energies

340
342
342
344
345

Ionic Bonding and Electron Transfer 345 Lattice Energy:
The Rest of the Story 346 Trends in Lattice Energies: Ion
Size 347 Trends in Lattice Energies: Ion Charge 347 Ionic
Bonding: Models and Reality 348

9.5 Covalent Bonding: lewis Structures

349

Single Covalent Bonds 349 Double and Triple Covalent
Bonds 350 Covalent Bonding: Models and Reality 350

9.6 Electronegativity and Bond Polarity

351

Electronegativity 352 Bond Polarity, Dipole Moment, and
Percent Ionic Character 353

9.7 lewis Structures of Molecular Compounds and
Polyatomic ions

356

Writing Lewis Structures for Molecular Compounds 356
Writing Lewis Structures for Polyatomic Ions 357

9.8 resonance and Formal Charge

358

Resonance 358 Formal Charge 360

9.9 Exceptions to the octet rule: odd-Electron Species,
incomplete octets, and Expanded octets
363
Odd-Electron Species 363 Incomplete Octets 363
Expanded Octets 364


Contents

ix

10.8 Molecular orbital Theory: Electron delocalization 409
Linear Combination of Atomic Orbitals (LCAO) 410
Period Two Homonuclear Diatomic Molecules 413

Chapter in review

420

Key Terms 420 Key Concepts 420 Key Equations and
Relationships 421 Key Learning Objectives 421

Exercises

421

Problems by Topic 421 Cumulative Problems 424
Challenge Problems 426 Conceptual Problems 426
Questions for Group Work 427 Answers to Conceptual
Connections 427

9.10 Bond Energies and Bond lengths

365

Bond Energy 366 Using Average Bond Energies to Estimate
Enthalpy Changes for Reactions 367 Bond Lengths 369

9.11 Bonding in Metals: The Electron Sea Model
Chapter in review

370
372

Key Terms 372 Key Concepts 372 Key Equations and
Relationships 373 Key Learning Objectives 373

Exercises

373

Problems by Topic 373 Cumulative Problems 375
Challenge Problems 376 Conceptual Problems 377
Questions for Group Work 377 Answers to Conceptual
Connections 377

11 liquids, Solids, and

10 Chemical Bonding ii:

Molecular Shapes, valence
Bond Theory, and Molecular
orbital Theory

intermolecular Forces

378

10.1 Artificial Sweeteners: Fooled by Molecular Shape 379
10.2 vSEPr Theory: The Five Basic Shapes
380
Two Electron Groups: Linear Geometry 381 Three Electron
Groups: Trigonal Planar Geometry 381 Four Electron
Groups: Tetrahedral Geometry 381 Five Electron Groups:
Trigonal Bipyramidal Geometry 382 Six Electron Groups:
Octahedral Geometry 383

10.3 vSEPr Theory: The Effect of lone Pairs

384

Four Electron Groups with Lone Pairs 384 Five Electron
Groups with Lone Pairs 386 Six Electron Groups with
Lone Pairs 387

10.4 vSEPr Theory: Predicting Molecular Geometries

388

Representing Molecular Geometries on Paper 391
Predicting the Shapes of Larger Molecules 391

10.5 Molecular Shape and Polarity
10.6 valence Bond Theory: orbital overlap as a
Chemical Bond
10.7 valence Bond Theory: Hybridization of
Atomic orbitals
3

2

392
395
397

sp Hybridization 399 sp Hybridization and Double

Bonds 400 sp Hybridization and Triple Bonds 404 sp3d
and sp3d2 Hybridization 405 Writing Hybridization and
Bonding Schemes 407

11.1 Water, No Gravity
11.2 Solids, liquids, and Gases: A Molecular
Comparison

428
429
430

Changes between States 432

11.3 intermolecular Forces: The Forces That Hold
Condensed States Together

432

Dispersion Force 433 Dipole–Dipole Force 435
Hydrogen Bonding 437 Ion–Dipole Force 439

11.4 intermolecular Forces in Action: Surface Tension,
viscosity, and Capillary Action
440
Surface Tension 441 Viscosity 441 Capillary Action 442

11.5 vaporization and vapor Pressure

442

The Process of Vaporization 442 The Energetics of
Vaporization 443 Heat of Vaporization 444 Vapor
Pressure and Dynamic Equilibrium 445 Temperature
Dependence of Vapor Pressure and Boiling Point 447 The
Clausius–Clapeyron Equation 448 The Critical Point: The
Transition to an Unusual State of Matter 450

11.6 Sublimation and Fusion

451

Sublimation 451 Fusion 452 Energetics of Melting and
Freezing 452

11.7 Heating Curve for Water
11.8 Phase diagrams

453
454

The Major Features of a Phase Diagram 454 Regions 454
Lines 455 The Triple Point 455 The Critical Point 455
Navigation within a Phase Diagram 456


x

Contents

12.7 Colligative Properties of Strong Electrolyte
Solutions

507

Strong Electrolytes and Vapor Pressure 508

Chapter in review

510

Key Terms 510 Key Concepts 510 Key Equations and
Relationships 511 Key Learning Objectives 511

Exercises

512

Problems by Topic 512 Cumulative Problems 514
Challenge Problems 516 Conceptual Problems 516
Questions for Group Work 517 Answers to Conceptual
Connections 517

11.9 Water: An Extraordinary Substance
456
11.10 Crystalline Solids: Unit Cells and Basic Structures 457
Closest-Packed Structures 461

11.11 Crystalline Solids: The Fundamental Types

463

Molecular Solids 464 Ionic Solids 464 Atomic
Solids 465

11.12 Crystalline Solids: Band Theory
Chapter in review

467
469

Key Terms 469 Key Concepts 469 Key Equations and
Relationships 470 Key Learning Objectives 471

Exercises

471

Problems by Topic 471 Cumulative Problems 475
Challenge Problems 476 Conceptual
Problems 476 Questions for Group Work 477 Answers
to Conceptual Connections 477

12 Solutions
12.1 Thirsty Solutions: Why You Should Not drink
Seawater
12.2 Types of Solutions and Solubility

478
479

481

Nature’s Tendency toward Mixing: Entropy 481 The Effect
of Intermolecular Forces 482

12.3 Energetics of Solution Formation

485

Aqueous Solutions and Heats of Hydration 486

12.4 Solution Equilibrium and Factors Affecting
Solubility

13.1 Catching lizards
13.2 The rate of a Chemical reaction
13.3 The rate law: The Effect of Concentration on
reaction rate

489

492

Molarity 493 Molality 494 Parts by Mass and Parts by
Volume 494 Mole Fraction and Mole Percent 495

12.6 Colligative Properties: vapor Pressure lowering,
Freezing Point depression, Boiling Point Elevation,
and osmotic Pressure
497

Vapor Pressure Lowering 498 Vapor Pressures of Solutions
Containing a Volatile (Nonelectrolyte) Solute 501 Freezing
Point Depression and Boiling Point Elevation 502
Osmosis 505

518
519
520
523

Determining the Order of a Reaction 525 Reaction Order
for Multiple Reactants 526

13.4 The integrated rate law: The dependence of
Concentration on Time

529

The Half-Life of a Reaction 533

13.5 The Effect of Temperature on reaction rate

The Temperature Dependence of the Solubility of
Solids 489 Factors Affecting the Solubility of Gases in
Water 490

12.5 Expressing Solution Concentration

13 Chemical Kinetics

536

Arrhenius Plots: Experimental Measurements of
the Frequency Factor and the Activation Energy 538
The Collision Model: A Closer Look at the Frequency
Factor 541

13.6 reaction Mechanisms

542

Rate Laws for Elementary Steps 542 Rate-Determining
Steps and Overall Reaction Rate Laws 543 Mechanisms
with a Fast Initial Step 544

13.7 Catalysis

546

Homogeneous and Heterogeneous
Catalysis 547 Enzymes: Biological Catalysts 548

Chapter in review

551

Key Terms 551 Key Concepts 551 Key Equations and
Relationships 552 Key Learning Objectives 552

xi

Contents

Finding Equilibrium Concentrations When We Are Given the
Equilibrium Constant and Initial Concentrations or
Pressures 580 Simplifying Approximations in Working
Equilibrium Problems 584

14.9 le Châtelier’s Principle: How a System at
Equilibrium responds to disturbances

588

The Effect of a Concentration Change on Equilibrium 588
The Effect of a Volume (or Pressure) Change on
Equilibrium 590 The Effect of a Temperature Change on
Equilibrium 591

Chapter in review

593

Key Terms 593 Key Concepts 594 Key Equations and
Relationships 594 Key Learning Objectives 595

Exercises
Exercises

552

Problems by Topic 552 Cumulative Problems 557
Challenge Problems 559 Conceptual Problems 560
Questions for Group Work 561 Answers to Conceptual
Connections 561

14 Chemical Equilibrium
14.1 Fetal Hemoglobin and Equilibrium
14.2 The Concept of dynamic Equilibrium
14.3 The Equilibrium Constant (K)

562
563
565
566

Expressing Equilibrium Constants for Chemical
Reactions 567 The Significance of the Equilibrium
Constant 568 Relationships between the Equilibrium
Constant and the Chemical Equation 569

14.4 Expressing the Equilibrium Constant in Terms
of Pressure

595

Problems by Topic 595 Cumulative Problems 599
Challenge Problems 600 Conceptual Problems 600
Questions for Group Work 601 Answers to Conceptual
Connections 601

15 Acids and Bases
15.1 Heartburn
15.2 The Nature of Acids and Bases
15.3 definitions of Acids and Bases

602
603
604
605

The Arrhenius Definition 606 The Brønsted–Lowry
Definition 606

571

Units of K 572

14.5 Heterogeneous Equilibria: reactions involving
Solids and liquids
14.6 Calculating the Equilibrium Constant from
Measured Equilibrium Concentrations
14.7 The reaction Quotient: Predicting the direction
of Change
14.8 Finding Equilibrium Concentrations

573
574
577
579

Finding Equilibrium Concentrations When We Are Given the
Equilibrium Constant and All but One of the Equilibrium
Concentrations of the Reactants and Products 579

15.4 Acid Strength and the Acid ionization
Constant (Ka)

608

Strong Acids 608 Weak Acids 609 The Acid Ionization
Constant (Ka) 610

15.5 Autoionization of Water and pH

611

The pH Scale: A Way to Quantify Acidity and Basicity 613
pOH and Other p Scales 615

15.6 Finding the [H3o∙] and pH of Strong and
Weak Acid Solutions

616

Strong Acids 616 Weak Acids 616 Polyprotic
Acids 620 Percent Ionization of a Weak Acid 622

15.7 Base Solutions

624

Strong Bases 624 Weak Bases 624 Finding the [OH-]
and pH of Basic Solutions 626


xii

Contents

15.8 The Acid–Base Properties of ions and Salts

627

Anions as Weak Bases 628 Cations as Weak Acids 631
Classifying Salt Solutions as Acidic, Basic, or Neutral 632

15.9 Acid Strength and Molecular Structure

634

Binary Acids 634 Oxyacids 635

15.10 lewis Acids and Bases

636

Molecules That Act as Lewis Acids 637 Cations That Act
as Lewis Acids 638

Chapter in review

Chapter in review

684

Key Terms 684 Key Concepts 684 Key Equations and
Relationships 684 Key Learning Objectives 685

Exercises

685

Problems by Topic 685 Cumulative Problems 688
Challenge Problems 690 Conceptual Problems 690
Questions for Group Work 691 Answers to Conceptual
Connections 691

639

Key Terms 639 Key Concepts 639 Key Equations and
Relationships 640 Key Learning Objectives 640

Exercises

640

Problems by Topic 640 Cumulative Problems 643
Challenge Problems 644 Conceptual Problems 645
Questions for Group Work 645 Answers to Conceptual

Connections 645

17 Free Energy and

Thermodynamics

16 Aqueous ionic Equilibrium
16.1 The danger of Antifreeze
16.2 Buffers: Solutions That resist pH Change

17.1 Nature’s Heat Tax: You Can’t Win and You
Can’t Break Even
17.2 Spontaneous and Nonspontaneous Processes
17.3 Entropy and the Second law of Thermodynamics
646
647
648

Calculating the pH of a Buffer Solution 650
The Henderson–Hasselbalch Equation 651 Calculating pH
Changes in a Buffer Solution 654 The Stoichiometry
Calculation 654 The Equilibrium Calculation 655 Buffers
Containing a Base and Its Conjugate Acid 657

16.3 Buffer Effectiveness: Buffer range and
Buffer Capacity

659

Relative Amounts of Acid and Base 659 Absolute

Concentrations of the Acid and Conjugate
Base 659 Buffer Range 660 Buffer Capacity 661

16.4 Titrations and pH Curves

662

The Titration of a Strong Acid with a Strong Base 663
The Titration of a Weak Acid with a Strong Base 666
The Titration of a Weak Base with a Strong Acid 672
The Titration of a Polyprotic Acid 672 Indicators: pHDependent Colors 673

16.5 Solubility Equilibria and the Solubility
Product Constant

675

Ksp and Molar Solubility 675 Ksp and Relative
Solubility 677 The Effect of a Common Ion on
Solubility 677 The Effect of pH on Solubility 679

16.6 Precipitation
16.7 Complex ion Equilibria

692
694
695
696

Entropy 697 The Entropy Change Associated with a

Change in State 702

17.4 Heat Transfer and Changes in the Entropy of the
Surroundings

703

The Temperature Dependence of ∆Ssurr 704 Quantifying
Entropy Changes in the Surroundings 704

17.5 Gibbs Free Energy

706

The Effect of ∆H, ∆S, and T on Spontaneity 708

17.6 Entropy Changes in Chemical reactions:
Calculating 𝚫S∙rxn

709

Standard Molar Entropies (S°) and the Third Law of
Thermodynamics 710

17.7 Free Energy Changes in Chemical
reactions: Calculating 𝚫G∙rxn

714

Calculating Free Energy Changes with

∆G°rxn = ∆H°rxn - T∆S°rxn 714 Calculating ∆G°rxn with
Tabulated Values of Free Energies of Formation 715
Calculating ∆G°rxn for a Stepwise Reaction from the
Changes in Free Energy for Each of the Steps 717 Why
Free Energy Is “Free” 718

17.8 Free Energy Changes for Nonstandard States:
The relationship between 𝚫G∙rxn and 𝚫Grxn

719

The Free Energy Change of a Reaction Under Nonstandard
Conditions 720 Standard Conditions 720 Equilibrium
Conditions 721 Other Nonstandard Conditions 721
680
681

17.9 Free Energy and Equilibrium: relating 𝚫G∙rxn to the
Equilibrium Constant (K)
722


xiii

Contents

Chapter in review

725

Key Terms 725 Key Concepts 726 Key Equations and
Relationships 726 Key Learning Objectives 727

Exercises

727

Problems by Topic 727 Cumulative Problems 730
Challenge Problems 731 Conceptual Problems 732
Questions for Group Work 732 Answers to Conceptual
Connections 733

19 radioactivity and Nuclear
Chemistry

19.1 diagnosing Appendicitis
19.2 Types of radioactivity

776
777
778

Alpha (a) Decay 779 Beta (b) Decay 780 Gamma (g)
Ray Emission 781 Positron Emission 781 Electron
Capture 781

19.3 The valley of Stability: Predicting the Type of
radioactivity

783

Magic Numbers 785 Radioactive Decay Series 785

18 Electrochemistry

734

18.1 Pulling the Plug on the Power Grid
735
18.2 Balancing oxidation–reduction Equations
736
18.3 voltaic (or Galvanic) Cells: Generating Electricity from
Spontaneous Chemical reactions
739
Electrochemical Cell Notation 741

18.4 Standard Electrode Potentials

742

Predicting the Spontaneous Direction of an Oxidation–
Reduction Reaction 747 Predicting Whether a Metal Will
Dissolve in Acid 749

18.5 Cell Potential, Free Energy, and
the Equilibrium Constant

749

The Relationship between ∆G° and E°cell 750

The Relationship between E°cell and K 751

18.6 Cell Potential and Concentration

753

Dry-Cell Batteries 757 Lead–Acid Storage Batteries 758
Other Rechargeable Batteries 758 Fuel Cells 759
760

Stoichiometry of Electrolysis 763
764

Preventing Corrosion 766

Chapter in review

767

Key Terms 767 Key Concepts 767 Key Equations and
Relationships 768 Key Learning Objectives 769

Exercises

The Integrated Rate Law 787 Radiocarbon Dating: Using
Radioactivity to Measure the Age of Fossils and
Artifacts 788 Uranium>Lead Dating 790

19.5 The discovery of Fission: The Atomic Bomb and
Nuclear Power

791

Nuclear Power: Using Fission to Generate Electricity 793

19.6 Converting Mass to Energy: Mass defect and
Nuclear Binding Energy

794

Mass Defect 795

19.7 Nuclear Fusion: The Power of the Sun
19.8 The Effects of radiation on life

797
798

19.9 radioactivity in Medicine

800

Diagnosis in Medicine 800 Radiotherapy in Medicine 801

18.7 Batteries: Using Chemistry to Generate Electricity 757

18.9 Corrosion: Undesirable redox reactions

785

Acute Radiation Damage 798 Increased Cancer Risk 798
Genetic Defects 798 Measuring Radiation Exposure 798

Concentration Cells 756

18.8 Electrolysis: driving Nonspontaneous Chemical
reactions with Electricity

19.4 The Kinetics of radioactive decay and
radiometric dating

769

Problems by Topic 769 Cumulative Problems 772
Challenge Problems 773 Conceptual Problems 774
Questions for Group Work 774 Answers to Conceptual
Connections 775

Chapter in review

802

Key Terms 802 Key Concepts 803 Key Equations and
Relationships 804 Key Learning Objectives 804

Exercises

804

Problems by Topic 804 Cumulative Problems 806

Challenge Problems 806 Conceptual Problems 807
Questions for Group Work 807 Answers to Conceptual
Connections 807
Appendix I
A-1
Appendix II

A-7

Appendix III

A-17

Appendix IV

A-42

Glossary

G-1

Credits

C-1

Index

i-1

This page intentionally left blank


Preface
To the Student
As you begin this course, I invite you to think about your
reasons for enrolling in it. Why are you taking general
chemistry? More generally, why are you pursuing a college
education? If you are like most college students taking general chemistry, part of your answer is probably that this
course is required for your major and that you are pursuing
a college education so you can get a good job someday.
While these are good reasons, I suggest a better one. I think
the primary reason for your education is to prepare you to
live a good life. You should understand chemistry—not for
what it can get you—but for what it can do for you.
Understanding chemistry, I believe, is an important source
of happiness and fulfillment. Let me explain.
Understanding chemistry helps you to live life to its fullest for two basic reasons. The first is intrinsic: Through an
understanding of chemistry, you gain a powerful appreciation
for just how rich and extraordinary the world really is. The
second reason is extrinsic: Understanding chemistry makes
you a more informed citizen—it allows you to engage with
many of the issues of our day. In other words, understanding
chemistry makes you a deeper and richer person and makes
your country and the world a better place to live. These reasons have been the foundation of education from the very
beginnings of civilization.
How does chemistry help prepare you for a rich life and
conscientious citizenship? Let me explain with two examples.
My first one comes from the very first page of Chapter 1 of
this book. There, I ask the following question: What is the

most important idea in all of scientific knowledge? My
answer to that question is this: The properties of matter are
determined by the properties of molecules and atoms. That
simple statement is the reason I love chemistry. We humans
have been able to study the substances that compose the world
around us and explain their behavior by reference to particles
so small that they can hardly be imagined. If you have never
realized the remarkable sensitivity of the world we can see to
the world we cannot, you have missed out on a fundamental
truth about our universe. To have never encountered this truth
is like never having read a play by Shakespeare or seen a
sculpture by Michelangelo—or, for that matter, like never
having discovered that the world is round. It robs you of an
amazing and unforgettable experience of the world and the
human ability to understand it.
My second example demonstrates how science literacy
helps you to be a better citizen. Although I am largely sympathetic to the environmental movement, a lack of science literacy within some sectors of that movement, and the resulting
anti-environmental backlash, creates confusion that impedes
real progress and opens the door to what could be misinformed policies. For example, I have heard conservative pundits say that volcanoes emit more carbon dioxide—the most

significant greenhouse gas—than does petroleum combustion. I have also heard a liberal environmentalist say that we
have to stop using hairspray because it is causing holes in the
ozone layer that will lead to global warming. Well, the claim
about volcanoes emitting more carbon dioxide than petroleum
combustion can be refuted by the basic tools you will learn to
use in Chapter 4 of this book. We can easily show that volcanoes emit only 1/50th as much carbon dioxide as petroleum
combustion. As for hairspray depleting the ozone layer and
thereby leading to global warming: The chlorofluorocarbons
that deplete ozone have been banned from hairspray since
1978, and ozone depletion has nothing to do with global

warming anyway. People with special interests or axes to
grind can conveniently distort the truth before an ill-informed
public, which is why we all need to be knowledgeable.
So this is why I think you should take this course. Not
just to satisfy the requirement for your major, and not just to
get a good job someday, but also to help you to lead a fuller
life and to make the world a little better for everyone. I wish
you the best as you embark on the journey to understand the
world around you at the molecular level. The rewards are well
worth the effort.

To the Professor
First and foremost, thanks to all of you who adopted this book
in its first and second editions. You helped to make this book
successful and I am grateful beyond words. Second, I have
listened carefully to your feedback on the previous edition.
The changes you see in this edition are a direct result of your
input, as well as my own experience in using the book in my
general chemistry courses. If you have acted as a reviewer or
have contacted me directly, you are likely to see your suggestions reflected in the changes I have made. The goal of this
edition remains the same: to present a rigorous and accessible treatment of general chemistry in the context of relevance.
Teaching general chemistry would be much easier if all of
our students had exactly the same level of preparation and ability.
But alas, that is not the case. Even though I teach at a relatively
selective institution, my courses are populated with students with
a range of backgrounds and abilities in chemistry. The challenge
of successful teaching, in my opinion, is therefore figuring out
how to instruct and challenge the best students while not losing
those with lesser backgrounds and abilities. My strategy has
always been to set the bar relatively high, while at the same time

providing the motivation and support necessary to reach the high
bar. That is exactly the philosophy of this book. We do not have
to compromise away rigor in order to make chemistry accessible
to our students. In this book, I have worked hard to combine rigor
with accessibility—to create a book that does not dilute the content, yet can be used and understood by any student willing to put
in the necessary effort.

xv


xvi

Preface

Principles of Chemistry: A Molecular Approach is first a
student-oriented book. My main goal is to motivate students
and get them to achieve at the highest possible level. As we all
know, many students take general chemistry because it is a
requirement; they do not see the connection between chemistry and their lives or their intended careers. Principles of
Chemistry: A Molecular Approach strives to make those connections consistently and effectively. Unlike other books,
which often teach chemistry as something that happens only
in the laboratory or in industry, this book teaches chemistry in
the context of relevance. It shows students why chemistry is
important to them, to their future careers, and to their world.
Second, Principles of Chemistry: A Molecular Approach
is a pedagogically-driven book. In seeking to develop problem-solving skills, a consistent approach (Sort, Strategize,
Solve, and Check) is applied, usually in a two- or three-column
format. In the two-column format, the left column shows the
student how to analyze the problem and devise a solution
strategy. It also lists the steps of the solution, explaining the

rationale for each one, while the right column shows the implementation of each step. In the three-column format, the left
column outlines a general procedure for solving an important
category of problems that is then applied to two side-by-side
examples. This strategy allows students to see both the general
pattern and the slightly different ways in which the procedure
may be applied in differing contexts. The aim is to help students understand both the concept of the problem (through the
formulation of an explicit conceptual plan for each problem)
and the solution to the problem.
Third, Principles of Chemistry: A Molecular Approach is a
visual book. Wherever possible, images are used to deepen the
student’s insight into chemistry. In developing chemical principles, multipart images help to show the connection between
everyday processes visible to the unaided eye and what atoms
and molecules are actually doing. Many of these images have
three parts: macroscopic, molecular, and symbolic. This combination helps students to see the relationships between the formulas they write down on paper (symbolic), the world they see
around them (macroscopic), and the atoms and molecules that
compose that world (molecular). In addition, most figures are
designed to teach rather than just to illustrate. They are rich with
annotations and labels intended to help the student grasp the
most important processes and the principles that underlie them.
The resulting images contain significant amounts of information but are also uncommonly clear and quickly understood.
Fourth, Principles of Chemistry: A Molecular Approach is
a “big picture” book. At the beginning of each chapter, a short
introduction helps students to see the key relationships between
the different topics they are learning. Through focused and
concise narrative, I strive to make the basic ideas of every
chapter clear to the student. Interim summaries are provided at
selected spots in the narrative, making it easier to grasp (and
review) the main points of important discussions. And to make
sure that students never lose sight of the forest for the trees,
each chapter includes several Conceptual Connections, which

ask them to think about concepts and solve problems without
doing any math. I want students to learn the concepts, not just
plug numbers into equations to churn out the right answer.

Principles of Chemistry: A Molecular Approach is, lastly, a
book that delivers the core of the standard chemistry curriculum,
without sacrificing depth of coverage. Through our research, we
have determined the topics that most faculty do not teach and we
have eliminated them. When writing a brief book, the temptation
is great to cut out the sections that show the excitement and relevance of chemistry; we have not done that here. Instead, we
have cut out pet topics that are often included in books simply to
satisfy a small minority of the market. We have also eliminated
extraneous material that does not seem central to the discussion.
The result is a lean book that covers core topics in depth, while
still demonstrating the relevance and excitement of these topics.
I hope that this book supports you in your vocation of
teaching students chemistry. I am increasingly convinced of
the importance of our task. Please feel free to email me with
any questions or comments about the book.
Nivaldo J. Tro


What’s New in This Edition?
The third edition has been extensively revised and contains
many more small changes than I can detail here. Below is a
list of the most significant changes from the previous edition.
• Morerobustmediacomponentshavebeenadded,including
80 Interactive Worked Examples, 39 Key Concept Videos,
14 additional Pause & Predict videos, 33 PHET simulations, and 5 new Mastering simulations with tutorials.
• Each chapter now has a 10–15 question multiple-choice

end-of-chapter Self-Assessment Quiz. Since many colleges and universities use multiple-choice exams, and because
standardized final exams are often multiple choice, students can use these quizzes to both assess their knowledge
of the material in the chapter and to prepare for exams.
These quizzes are also available on mobile devices.
• Approximately 100 new end-of-chapter group work
questions have been added to encourage small group work
in or out of the classroom.
• Approximately45newend-of-chapterproblemshavebeen
added.
• New conceptual connections have been added and many
from the previous edition have been modified. In addition,
to support active, in class, learning, these questions are
now available in Learning Catalytics.
• All data have been updated to the most recent available.
See for example:
Section 1.7 The Reliability of a Measurement in which
the data in the table of carbon monoxide concentrations in Los Angeles County (Long Beach) have been
updated.
Figure 4.2 Carbon Dioxide Concentrations in the Atmosphere is updated to include information through 2013.
Figure 4.3 Global Temperature is updated to include information through 2013.
Figure 4.19 U.S. Energy Consumption is updated to include the most recent available information.


Preface

• Manyfiguresandtableshavebeenrevisedforclarity.See,
for example:
Figure 3.6 Metals Whose Charge Is Invariant in
Section 3.5. This replaces Table 3.2 Metals Whose
Charge Is Invariant from One Compound to Another.

The weather map in Section 5.2 has been replaced, and
the caption for the weather map has been simplified
and linked more directly to the text discussion.
Figure 7.3 Components of White Light has been replaced with a corrected image of light passing through
a prism.
Figure 7.4 The Color of an Object and Figure 7.17 The
Quantum-Mechanical Strike Zone both have updated
photos.
The orbital diagram figure in Section 7.5 Quantum
Mechanics and the Atom that details the various principal levels and sublevels has been replaced with an updated version that is more student-friendly and easier
to navigate.
Figure 8.2 Shielding and Penetration is modified so
that there is a clear distinction between parts a and b.
Figure 10.15 Molecular Orbital Energy Diagrams for
Second-Row Homonuclear Diatomic Molecules now
has magnetic properties and valence electron configuration information.
Figure 12.10 Solubility and Temperature. Data for
Na2SO4 have been deleted from the graph, and data
Ce2(SO4)3 have been added to the graph.
Figure 13.11 Thermal Energy Distribution is modified.
It is now noted in the caption that Ea is a constant and
does not depend on temperature; new notations have
also been added to the figure.
Table 15.5 Acid Ionization Constants for Some Monoprotic Weak Acids at 25 °C has been modified to include pKa values.
The unnumbered photo of a fuel cell car in Section
18.1 Pulling the Plug on the Power Grid has been replaced with an updated image of a newer fuel cell car.
• InSection10.5andthroughoutChapter11,theuseofelectrostatic potential maps has been expanded. See, for example, Figures 11.6, 11.7, 11.9, and 11.10.
• In Section 10.8 Molecular Orbital Theory: Electron Delocalization in the subsection on Linear Combination of
Atomic Orbitals (LCAO), a discussion of molecular orbital
electron configuration has been added.

• New chapter-opening art, briefer introductory material,
and a new first section (11.1 Water, No Gravity) replace
Section 11.1.
• InSection13.4The Integrated Rate Law: The Dependence
of Concentration on Time, the derivation to integrate the
differential rate law to obtain the first-order integrated rate
law is now shown in a margin note.
• TheformatforalltheICEtablesisnewinChapters14,15,
and 16; the format has been modified to make them easier
to read.

xvii

• AnewsectionentitledThe Titration of a Polyprotic Acid
has been added to Section 16.4 Titrations and Curves.
Content includes new Figure 16.8 Titration Curve: Diprotic Acid with Strong Base.
• Some newin-chapterexamples havebeenadded,including Example 4.14 Writing Equations for Acid–Base Reactions Involving a Weak Acid and Example 9.9 Drawing
Resonance Structures and Assigning Formal Charge for
Organic Compounds.

Acknowledgments
The book you hold in your hands bears my name on the cover,
but I am really only one member of a large team that carefully crafted this book. Most importantly, I thank my editor,
Terry Haugen, who has become a friend and colleague. Terry
is a skilled and competent editor. He has given me direction,
inspiration, and most importantly, loads of support. I am just
as grateful for my program manager, Jessica Moro, and project manager, Beth Sweeten, who have worked tirelessly
behind the scenes to bring this project to completion. I continue to be grateful for Jennifer Hart in her new role overseeing development. Jennifer, your guidance and wisdom are
central to the success of my projects, and I am eternally grateful. I am also grateful to Caitlin Falco who helped with organizing reviews, as well as numerous other tasks associated
with keeping the team running smoothly. I also thank Erin

Mulligan, who has now worked with me on many projects.
Erin is an outstanding developmental editor who not only
worked with me on crafting and thinking through every word
but is now also a friend and fellow foodie. I am also grateful
to Adam Jaworski. Adam has become a fantastic leader at
Pearson and a friend to me. Thanks also to Dave Theisen, who
has been selling my books for 15 years and has become a
great friend. Dave, I appreciate your tireless efforts, your professionalism, and your in-depth knowledge of my work. And
of course, I am continually grateful for Paul Corey, with
whom I have now worked for over 14 years and a dozen
books. Paul is a man of incredible energy and vision, and it is
my great privilege to work with him. Paul told me many years
ago (when he first signed me on to the Pearson team) to dream
big, and then he provided the resources I needed to make
those dreams come true. Thanks, Paul. I would also like to
thank my first editor at Pearson, Kent Porter-Hamann. Kent
and I spent many good years together writing books, and I
continue to miss her presence in my work.
I am also grateful to my marketing managers, Will Moore
and Chris Barker, who have helped to develop a great marketing campaign for my books and are all good friends. I am
deeply grateful to Gary Hespenheide for crafting the design of
this text. I would like to thank Beth Sweeten and the rest of
the Pearson production team. I also thank Francesca Monaco
and her co-workers at CodeMantra. I am a picky author and
Francesca is endlessly patient and a true professional. I am
also greatly indebted to my copy editor, Betty Pessagno, for
her dedication and professionalism, and to Lauren McFalls,
for her exemplary photo research. I owe a special debt of
gratitude to Quade and Emiko Paul, who continue to make my

xviii

Preface

ideas come alive in their art. Thanks also to Derek Bacchus
for his work on the cover and with design.
I would like to acknowledge the help of my colleagues
Allan Nishimura, Michael Everest, Kristi Lazar, Steve
Contakes, David Marten, and Carrie Hill, who have supported
me in my department while I worked on this book. Double
thanks to Michael Everest for also authoring the Questions for
Group Work. I am also grateful to those who have supported
me personally. First on that list is my wife, Ann. Her love
rescued a broken man fifteen years ago and without her, none
of this would have been possible. I am also indebted to my
children, Michael, Ali, Kyle, and Kaden, whose smiling faces
and love of life always inspire me. I come from a large Cuban
family whose closeness and support most people would envy.
Thanks to my parents, Nivaldo and Sara; my siblings, Sarita,
Mary, and Jorge; my siblings-in-law, Nachy, Karen, and John;
my nephews and nieces, Germain, Danny, Lisette, Sara, and
Kenny. These are the people with whom I celebrate life.
I would like to thank all of the general chemistry students
who have been in my classes throughout my years as a professor at Westmont College. You have taught me much about
teaching that is now in this book. I would also like to express
my appreciation to Michael Tro, who also helped in manuscript development, proofreading, and working new problems.
Lastly, I am indebted to the many reviewers whose ideas
are embedded throughout this book. They have corrected me,
inspired me, and sharpened my thinking on how best to teach

this subject we call chemistry. I deeply appreciate their commitment to this project. Thanks also to Frank Lambert for
helping us all to think more clearly about entropy and for his
review of the entropy sections of the book. Last but by no
means least, I would like to record my gratitude to Brian
Gute, Milton Johnston, Jessica Parr, and John Vincent whose
alertness, keen eyes, and scientific astuteness help make this
a much better book.

reviewers
Patrice Bell, Georgia Gwinnett College
Sharmaine Cady, East Stroudsburg University
James Cleveland, Northeast State Community College
Chris Collinson, Rochester Institute of Technology
Charlie Cox, Stanford University
Brent Cunningham, James Madison University
Bridget Decker, University of Wyoming-Laramie
William Deese, Louisiana Tech University
Dawn Del Carlo, University of Northern Iowa
Steve Everly, Lincoln Memorial University
Daniel Finnen, Shawnee State University
Paul Fischer, Macalester College
David Geiger, The State University of New York (Geneseo)
Patricia Goodson, University of Wyoming
Burt Hollandsworth, Harding University
Matthew Horn, Utah Valley University
Mary Elizabeth Kinsel, Southern Illinois University
Gerald Korenowski, Rensselaer Polytechnic Institute
Hoitung Leung, University of Virginia

Clifford Padgett, Armstrong State University

Andrew Price, Temple University
Jennifer Schwartz Poehlmann, Stanford University
Anthony Smith, Walla Walla University
Thomas Sorensen, University of Wisconsin (Milwaukee)
Kara Tierney, Monroe Community College
Rosie Walker, Metropolitan State University of Denver

Accuracy reviewers
Brian Gute, University of Minnesota, Duluth
Milton Johnston, University of South Florida
Jessica Parr, University of Southern California
John Vincent, University of Alabama

Previous Edition reviewers
Patricia G. Amateis, Virginia Tech
T.J. Anderson, Francis Marion University
Paul Badger, Robert Morris University
Yiyan Bai, Houston Community College
Maria Ballester, Nova Southeastern University
Rebecca Barlag, Ohio University
Shuhsien Batamo, Houston Community College (Central
Campus)
Craig A. Bayse, Old Dominion University
Maria Benavides, University of Houston, Downtown
Charles Benesh, Wesleyan College
Silas C. Blackstock, University of Alabama
Justin Briggle, East Texas Baptist University
Ron Briggs, Arizona State University
Katherine Burton, Northern Virginia Community College
David A. Carter, Angelo State University

Linda P. Cornell, Bowling Green State University, Firelands
Charles T. Cox, Jr., Georgia Institute of Technology
David Cunningham, University of Massachusetts, Lowell
Michael L. Denniston, Georgia Perimeter College
Ajit S. Dixit, Wake Technical Community College
David K. Erwin, Rose-Hulman Institute of Technology
Giga Geme, University of Central Missouri
Vincent P. Giannamore, Nicholls State University
Pete Golden, Sandhills Community College
Robert A. Gossage, Acadia University
Susan Hendrickson, University of Colorado (Boulder)
Angela Hoffman, University of Portland
Andrew W. Holland, Idaho State University
Narayan S. Hosmane, Northern Illinois University
Jason C. Jones, Francis Marion University
Jason A. Kautz, University of Nebraska, Lincoln
Chulsung Kim, Georgia Gwinnett College
Scott Kirkby, East Tennessee State University
Richard H. Langley, Stephen F. Austin State University
Christopher Lovallo, Mount Royal College
Eric Malina, University of Nebraska, Lincoln
David H. Metcalf, University of Virginia
Dinty J. Musk, Jr., Ohio Dominican University
Edward J. Neth, University of Connecticut
MaryKay Orgill, University of Nevada, Las Vegas


Preface

Gerard Parkin, Columbia University

BarJean Phillips, Idaho State University
Nicholas P. Power, University of Missouri
Changyong Qin, Benedict College
William Quintana, New Mexico State University
Valerie Reeves, University of New Brunswick
Dawn J. Richardson, Collin College
Thomas G. Richmond, University of Utah
Melinda S. Ripper, Butler County Community College
Jason Ritchie, The University of Mississippi
Christopher P. Roy, Duke University
Jamie Schneider, University of Wisconsin (River Falls)
John P. Scovill, Temple University
Thomas E. Sorensen, University of Wisconsin, Milwaukee
Vinodhkumar Subramaniam, East Carolina University
Dennis Swauger, Ulster County Community College
Ryan Sweeder, Michigan State University
Chris Syvinski, University of New England
Dennis Taylor, Clemson University
David Livingstone Toppen, California State University,
Northridge
Harold Trimm, Broome Community College
Tommaso A. Vannelli, Western Washington University
Kristofoland Varazo, Francis Marion University
Susan Varkey, Mount Royal College
Joshua Wallach, Old Dominion University
Clyde L. Webster, University of California, Riverside

xix

Wayne Wesolowski, University of Arizona

Kurt Winkelmann, Florida Institute of Technology
Edward P. Zovinka, Saint Francis University

Previous Edition Accuracy reviewers
Margaret Asirvatham, University of Colorado, Boulder
Rebecca Barlag, Ohio University
Angela Hoffman, University of Portland
Louis Kirschenbaum, University of Rhode Island
Richard Langley, Stephen F. Austin State University
Kathleen Thrush Shaginaw, Particular Solutions, Inc.
Sarah Siegel, Gonzaga University
Steven Socol, McHenry County College

Focus Group Participants
Yiyan Bai, Houston Community College
Silas Blackstock, University of Alabama
Jason Kautz, University of Nebraska (Lincoln)
Michael Mueller, Rose-Hulman Institute of Technology
Tom Pentecost, Grand Valley State University
Andrew Price, Temple University
Cathrine Reck, Indiana University
Sarah Siegel, Gonzaga University
Shusien Wang-Batamo, Houston Community College
Lin Zhu, Indiana University–Purdue University Indianapolis


Chemistry through Relevancy
Chemistry is relevant to every process occurring around us at every second. Niva
Tro helps students understand this connection by weaving specific, vivid examples
throughout the text and media that tell the story of chemistry. Every chapter begins

with a brief story showing how chemistry is relevant to all people, at every moment.

It’s a wild dance floor there at the molecular level.
—Roald Hoffmann (1937–)

11

Liquids, Solids, and Intermolecular
Forces

W

E LEARNED IN CHAPTER 1 THAT
matter exists primarily in three

states: solid, liquid, and gas. In Chapter 5,
we examined the gas state. In this chapter
we turn to the solid and liquid states,
known collectively as the condensed states
(or condensed phases). The solid and liquid
states are more similar to each other than
they are to the gas state. In the gas state,
the constituent particles—atoms or
molecules—are separated by large
distances and do not interact with each
other very much. In the condensed states,
the constituent particles are close together
and exert moderate to strong attractive
forces on one another. Whether a
substance is a solid, liquid, or gas at room

temperature depends on the magnitude of
the attractive forces among the constituent
particles. In this chapter, we will see how

11.1 Water, No Gravity 429
11.2 Solids, Liquids, and Gases: A
Molecular Comparison 430
11.3 Intermolecular Forces: The
Forces That Hold Condensed
States Together 432
11.4 Intermolecular Forces in
Action: Surface Tension,
Viscosity, and Capillary
Action 440
11.5 Vaporization and Vapor
Pressure 442
11.6 Sublimation and Fusion 451
11.7 Heating Curve for Water 453
11.8 Phase Diagrams 454
11.9 Water: An Extraordinary
Substance 456
11.10 Crystalline Solids: Unit Cells
and Basic Structures 457
11.11 Crystalline Solids: The
Fundamental Types 463
11.12 Crystalline Solids: Band
Theory 467
Key Learning Objectives 471

the properties of a particular atom or

molecule determine the magnitude of those
In the absence of
gravity (such as in a
space station), a
sample of water sticks
together to form a
perfect sphere. This
behavior is a direct
result of intermolecular
forces—attractive
forces that exist
among the particles
that compose matter.

attractive forces.

11.1 Water, No Gravity
In the space station there are no spills. When an astronaut squeezes a full water bottle, the
water squirts out like it does on Earth, but instead of falling to the floor and forming a
puddle, the water sticks together to form a floating, oscillating, blob of water. Over time,
the blob stops oscillating and forms a nearly perfect sphere. Why?

429

160

Chapter 4

Chemical Quantities and Aqueous Reactions

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30/08/14 10:59 AM

M11_TRO1944_03_SE_C11_428-477v4.0.1.indd 429

Oxidation–Reduction Reaction without Oxygen
2 Na(s) + Cl2(g)

2 NaCl(s)

Electrons are transferred from sodium to chlorine, forming sodium chloride.
Sodium is oxidized and chlorine is reduced.

Na+
2 Na(s)

+

Cl 2

Electron
transfer

Cl2(g)

Na+
Cl–

NaCl(s)

Oxidation–Reduction without Oxygen When sodium reacts with chlorine, electrons
are transferred from the sodium to the chlorine, resulting in the formation of sodium chloride. In this
redox reaction, sodium is oxidized and chlorine is reduced.

▲ FiguRe 4.17

The reaction between sodium and oxygen
forms other oxides as well.

A helpful mnemonic is O I L R I G—Oxidation
Is Loss; Reduction Is Gain.

H

H

However, redox reactions need not involve oxygen. Consider, for example, the reaction between sodium and chlorine to form sodium chloride (NaCl), depicted in
FiguRe 4.17▲.
2 Na(s) + Cl2(g) S 2 NaCl(s)

δ

+

δ

H

Cl

–

Cl

This reaction is similar to the reaction between sodium and oxygen to form sodium oxide.
4 Na(s) + O2(g) S 2 Na 2O(s)

Cl

In both cases, a metal (which has a tendency to lose electrons) reacts with a nonmetal
(which has a tendency to gain electrons). In both cases, metal atoms lose electrons to
nonmetal atoms. A fundamental definition of oxidation is the loss of electrons, and a
fundamental definition of reduction is the gain of electrons.
The transfer of electrons, however, need not be a complete transfer (as occurs in the
formation of an ionic compound) for the reaction to qualify as oxidation–reduction. For
example, consider the reaction between hydrogen gas and chlorine gas:
H2(g) + Cl2(g) S 2 HCl(g)

Redox with Partial
Electron Transfer When hydrogen
bonds to chlorine, the electrons are
unevenly shared, resulting in an
increase of electron density (reduction)
for chlorine and a decrease in electron
density (oxidation) for hydrogen.
▲ FiguRe 4.18

Even though hydrogen monochloride is a molecular compound with a covalent bond, and
even though the hydrogen has not completely transferred its electron to chlorine during

the reaction, you can see from the electron density diagrams (FiguRe 4.18◀) that hydrogen
has lost some of its electron density—it has partially transferred its electron to chlorine.
Therefore, in this reaction, hydrogen is oxidized and chlorine is reduced and the reaction
is a redox reaction.

Visualizing Chemistry
30/08/14 10:59 AM

Student-friendly, multipart images include
macroscopic, molecular, and symbolic
perspectives with the goal of connecting
you to what you see and experience
(macroscopic) with the molecules
responsible for that world (molecular)
and with the way chemists represent
those molecules (symbolic). Illustrations
include extensive labels and annotations
to highlight key elements and to help
differentiate the most critical information
(white box) to secondary information
(beige box).


Interactive Problem-Solving
Strategy
129

4.2 Reaction Stoichiometry: How Much Carbon Dioxide?

Solution

We follow the conceptual plan to solve the problem, beginning with g C8H18 and canceling units to arrive at g CO2:
3.7 * 1015 g C8H18 *

44.01 g CO2
1 mol C8H18
16 mol CO2
*
*
= 1.1 * 1016 g CO2
114.22 g C8H18
2 mol C8H18
1 mol CO2
16

13

world’s petroleum combustion produces 1.1 * 10 g CO2 (1.1 * 10 kg) per year.
AThe
unique
yet consistent step-by-step format encourages
logical
thinking
The percentage
of CO emitted
by volcanoes
In comparison, volcanoes produce about 2.0 * 1011 kg CO2 per year.* In other words,
relative to all fossil fuels is even less than
11
because CO is
also emitted by the

throughout the
problem-solving
process rather than 2%simply
memorizing
2.0 *
10 kg
volcanoes emit only
* 100% = 1.8% as much CO2 per year as petrocombustion of coal and natural gas.
1.1 * 1013 kg
formulas.
leum combustion. The argument that volcanoes emit more carbon dioxide than fossil fuel
2

2

combustion is blatantly incorrect. Examples 4.1 and 4.2 provide additional practice with
stoichiometric calculations.

ExamPlE 4.1 Stoichiometry
During photosynthesis, plants convert carbon dioxide and water into glucose (C6H12O6) according to the reaction:
sunlight
6 CO2(g) + 6 H2O(l) ˚˚˚˚" 6 O2(g) + C6H12O6(aq)

Suppose a particular plant consumes 37.8 g CO2 in one week. Assuming that there is more than enough water present to
react with all of the CO2, what mass of glucose (in grams) can the plant synthesize from the CO2?
SORT The problem gives the mass
of carbon dioxide and asks you to
find the mass of glucose that can
be produced.

GIVEN 37.8 g CO2
FIND g C6H12O6

STRATEGIZE The conceptual plan follows the general pattern of mass
A S amount A (in moles) S
amount B (in moles) S mass B.
From the chemical equation, you
can deduce the relationship
between moles of carbon dioxide
and moles of glucose. Use the
molar masses to convert between
grams and moles.

CONCEPTUAL PLAN

SOLVE Follow the conceptual plan
to solve the problem. Begin with g
CO2 and use the conversion factors
to arrive at g C6H12O6.

g CO2

mol CO2

mol C6H12O6

g C6H12O6

1 mol CO2

1 mol C6H12O6

180.16 g C6H12O6

44.01 g CO2

6 mol CO2

1 mol C6H12O6

RELATIONSHIPS USED
molar mass CO2 = 44.01 g>mol
6 mol CO2 : 1 mol C6H12O6
molar mass C6H12O6 = 180.16 g>mol
SOLUTION
37.8 g CO2 *

1 mol C6H12O6
180.16 g C6H12O6
1 mol CO2
*
*
= 25.8 g C6H12O6
44.01 g CO2
6 mol CO2
1 mol C6H12O6

CHECK The units of the answer are correct. The magnitude of the answer (25.8 g) is less than the initial mass of
CO2 (37.8 g). This is reasonable because each carbon in CO2 has two oxygen atoms associated with it, while in C6H12O6
each carbon has only one oxygen atom associated with it and two hydrogen atoms, which are much lighter than oxygen.

Therefore the mass of glucose produced should be less than the mass of carbon dioxide for this reaction.

FOR PRACTICE 4.1
Magnesium hydroxide, the active ingredient in milk of magnesia, neutralizes stomach acid, primarily HCl, according to the
reaction:
Mg(OH)2(aq) + 2 HCl(aq) S 2 H2O(l) + MgCl2(aq)
What mass of HCl, in grams, is neutralized by a dose of milk of magnesia containing 3.26 g Mg (OH)2?

*

Gerlach, T. M., Present-day CO2 emissions from volcanoes; Eos, Transactions, American Geophysical Union,

Vol. 72, No. 23, June 4, 1991, pp. 249 and 254–255
NEW!
80 Interactive Worked Examples make Tro’s

unique problem-solving strategies interactive, bringing
his award-winning teaching directly to all students using
his text. In these digital, mobile versions, students are
instructed how to break down problems using Tro’s proven
Sort, Strategize, Solve, and Check technique.

M04_TRO1944_03_SE_C04_124-175v4.0.8.indd 129

17/10/14 11:12 AM

Icons appear next to
examples indicating a digital
version is available in the
etext and on mobile devices

via a QR code located here,
and on the back cover of your
textbook.


Use the Lewis structure, or any one of the
resonance structures, to determine the number of electron groups around the central
atom.

The nitrogen atom has th
Based on the number of electron groups,
determine the geometry that minimizes the
repulsions between the groups.

A Focus on Conceptual
Understanding

The electron geometry th
between three electron g
Because there are no lon
the molecular geometry i

Since the three bonds ar
the same repulsion on th
has three equal bond an

FOR PRACTICE 10.1
Determine the molecular geometry of CCl4.

Key Concept Videos

NEW! 39 Key Concept Videos combine artwork from the textbook
with both 2D and 3D animations to create a dynamic on-screen viewing
and learning experience. These short videos include narration and brief
live-action clips of author Niva Tro explaining the key concepts of each
chapter.

KEY CONCEPT VIDEO
VSEPR Theory: The Effect
of Lone Pairs

10.3 VSEPR Theory: T

Each of the examples we examine
around the central atom. What happ
tral atom as well? These lone pair
examples that follow.

Four Electron Groups wit

The Lewis structure of ammonia is s

The central nitrogen atom has four e
that repel one another. If we do not d
pairs, we find that the electron geo
groups—is still tetrahedral, as we ex
lar geometry—the geometrical arr
shown here.

H

N
H

Electron
geometry:
tetrahedra

Notice that although the electron ge
electron geometry is relevant to the m
on the bonding pairs.

M10_TRO1944_03_SE_C10_378-427v3.0.2.indd 384