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CHEMISTRY
The Central Science
SEVENTH EDITION
Theodore L. Brown
University of Illinois at Urbana-Champaign
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University of Nevada, Reno
ruce E. Bürsten
The Ohio State University
Prentice-Hall International, Inc.
Contents
Chemical Applications and Essays xvii
Preface xix
A Student's Guide to Using this Text xxvii
About the Authors xxxi
1 Introduction: Matter and Measurement 1
1.1 The Study of Chemistry 1
The Molecular Perspective of Chemistry 1 Why Study Chemistry? 2
1.2 Classification of Matter 5
States of Matter 5
Pure Substances and Mixtures 6
Separation of Mixtures 8
Elements 9
Compounds 10
1.3 Properties of Matter 11
Physical and Chemical Changes 11
1.4 Units of Measurement 14
SI Units 14
Length and Mass 15 Temperature 15
Derived SI Units 17
Volume 17
Density 17
1.5 Uncertainty in Measurement 21
Precision and Accuracy 22
Significant Figures 22
Significant Figures in Calculations 23
1.6 Dimensional Analysis 25
Summary of Dimensional Analysis 27
Summary and Key Terms 30
Exercises 31
2 Atoms, Molecules, and Ions
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2.1 The Atomic Theory of Matter 37
2.2 The Discovery of Atomic Structure 38
Cathode Rays and Electrons 39
Radioactivity 41
The Nuclear Atom 41
2.3 The Modern View of Atomic Structure 43
Isotopes, Atomic Numbers, and Mass Numbers 45
2.4 The Periodic Table 46
2.5 Molecules and Molecular Compounds 49
Molecules and Chemical Formulas 49 Molecular and Empirical Formulas 50
Picturing Molecules 51
2.6 Ions and Ionic Compounds 52
Predicting Ionic Charges 53 Ionic Compounds 54
2.7 Naming Inorganic Compounds 57
Names and Formulas of Ionic Compounds 58
Names and Formulas of Acids 62
Names and Formulas of Binary Molecular Compounds 63
Summary and Key Terms 64
Exercises 65
3 Stoichiometry: Calculations with Chemical Formulas and Equations
71
3.1 Chemical Equations 71
3.2 Patterns of Chemical Reactivity 74
Using the Periodic Table 74 Combustion in Air 75
V
Combinations and Decomposition Reactions 76
3.3 Atomic and Molecular Weights 78
The Atomic Mass Scale 78
Average Atomic Masses 78
Formula and Molecular Weights 79
Percentage Composition from Formulas 80
3.4 The Mole 81
Molar Mass 82
InterConverting Masses, Moles, and Numbers of Particles 84
3.5 Empirical Formulas from Analyses 86
Molecular Formula from Empirical Formula 88
Combustion Analysis 89
3.6 Quantitative Information from Balanced Equations 90
3.7 Limiting Reactants 93
Theoretical Yields 97
Summary and Key Terms 98
Exercises 99
4 Aqueous Reactions and Solution Stoichiometry
107
4.1 Solution Composition 107
Molarity 107
Dilution 110
4.2 Properties of Solutes in Aqueous Solution 112
lonic Compounds in Water 113 Molecular Compounds in Water 114
Strong and Weak Electrolytes 115
4.3 Acids, Bases, and Salts 115
Acids 116 Bases 116
Strong and Weak Acids and Bases 117
Neutralization Reactions and Salts 118
4.4 lonic Equations 119
4.5 Metathesis Reactions 121
Precipitation Reactions 122
Solubility Guidelines for lonic Compounds 122
Reactions in Which a Weak Electrolyte or Nonelectrolyte Forms 124
Reactions in Which a Gas Forms 126
4.6 Introduction to Oxidation-Reduction Reactions 128
Oxidation and Reduction 129
Oxidation of Metals by Acids and Salts 129
The Activity Series 130
4.7 Solution Stoichiometry and Chemical Analysis 133
Titrations 136
Summary and Key Terms 138
Exercises 139
5 Thermochemistry 145
5.1 The Nature of Energy 145
Kinetic and Potential Energy 146
Energy Units 146
Systems and Surroundings 147
5.2 The First Law of Thermodynamics 147
Internal Energy 148 Relating A£ to Heat and Work 148
Endothermic and Exothermic Processes 149 State Functions 150
5.3 Enthalpy 151
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5.4 Enthalpies of Reactions 154
5.5 Calorimetry 156
Heat Capacity and Specific Heat 157 Constant-Pressure Calorimetry 159
Bomb Calorimetry (Constant-Volume Calorimetry) 160
5.6 Hess'sLaw 162
5.7 Enthalpies of Formation 164
Contents
Using Enthalpies of Formation to Calculate Enthalpies of Reaction 165
5.8 Foods and Fuels 170
Foods 170 Fuels 172 Other Energy Sources 173
Summary and Key Terms 174
Exercises 175
6 Electronic Structure of Atoms 183
6.1 The Wave Nature of Light 183
6.2 Quantized Energy and Photons 185
The Photoelectric Effect 187
6.3 Bohr's Model of the Hydrogen Atom 189
LineSpectra 189 Bohr's Model 190
6.4 The Wave Behavior of Matter 194
The Uncertainty Principle 195
6.5 Quantum Mechanics and Atomic Orbitals 195
Orbitals and Quantum Numbers 197
6.6 Representations of Orbitals 199
The s Orbitals 200 The p Orbitals 201
The d and / Orbitals 201
6.7 Orbitals in Many-Electron Atoms 202
Effective Nuclear Charge 203 Energies of Orbitals 203
Electron Spin and the Pauli Exclusion Principle 204
6.8 Electron Configurations 206
Periods 1, 2, and 3 206 Period 4 and Beyond 210
6.9 Electron Configurations and the Periodic Table 211
Summary and Key Terms 215
Exercises 217
7 Periodic Properties of the Elements 223
7.1 Development of the Periodic Table 223
7.2 Electron Shells and the Sizes of Atoms 225
Electron Shells in Atoms 225
Atomic Sizes 226
7.3 Ionization Energy 229
Periodic Trends in Ionization Energies 230
7.4 Electron Affinities 232
7.5 Metals, Nonmetals, and Metalloids 234
Metals 235 Nonmetals 237
Metalloids 238
7.6 Group Trends for the Active Metals 239
Group 1A: The Alkali Metals 239 Group 2A: The Alkaline Earth Metals 241
7.7 Group Trends for Selected Nonmetals 243
Hydrogen 243 Group 6A: The Oxygen Family 244
Group 7A: The Halogens 245
Group 8A: The Noble Gases 246
Summary and Key Terms 248
Exercises 249
8 Basic Concepts of Chemical Bonding
8.1
8.2
8.3
255
Lewis Symbols and the Octet Rule 255
Ionic Bonding 256
Energetics of Ionic Bond Formation 258
Electron Configuration of Ions of the Representative Elements 259
Transition-Metal Ions 262
Polyatomic Ions 262
Size of Ions 263
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8.4
Covalent Bonding 264
Multiple Bonds 266
8.5 Bond Polarity and Electronegativity 266
Electronegativity 267
Electronegativity and Bond Polarity 268
8.6 Drawing Lewis Structures 269
Formal Charge 271
8.7 Resonance Structures 273
Resonance in Benzene 275
8.8 Exceptions to the Octet Rule 276
Odd Number of Electrons 276 Less Than an Octet 276
More Than an Octet 277
8.9 Strengths of Covalent Bonds 279
Bond Enthalpies and the Enthalpies of Reactions 280
Bond Strength and Bond Length 282
8.10 Oxidation Numbers 284
Oxidation Numbers and Nomenclature 287
Summary and Key Terms 287
Exercises 289
9 Molecular Geometry and Bonding Theories 295
9.1 Molecular Shapes 295
9.2 The VSEPR Model 296
Predicting Molecular Geometries 297
The Effect of Nonbonding Electrons and Multiple Bonds on Bond Angles 300
Molecules with Expanded Valence Shells 303
Molecules with More than One Central Atom 304
9.3 Polarity of Molecules 305
Dipole Moments of Polyatomic Molecules 307
9.4 Covalent Bonding and Orbital Overlap 309
9.5 Hybrid Orbitals 311
sp Hybrid Orbitals 311 sp2 and sp3 Hybrid Orbitals 313
Hybridization Involving d Orbitals 314 Summary 315
9.6 Multiple Bonds 317
Delocalized JT Bonding 320
General Conclusions 323
9.7 Molecular Orbitals 324
The Hydrogen Molecule 324
Bond Order 326
9.8 Second-Row Diatomic Molecules 327
Molecular Orbitals for Li2 and Be2 327
Molecular Orbitals from 2p Atomic Orbitals 329
Electron Configurations for B2 through Ne 2 330
Electron Configurations and Molecular Properties 332
Summary and Key Terms 335
Exercises 336
1 0 Gases 343
10.1 Characteristics of Gases 343
10.2 Pressure 344
Atmospheric Pressure and the Barometer 344
Properties of Enclosed Gases and Manometers 346
10.3 T h e G a s L a w s 349
Contents
The Pressure-Volume Relationship: Boyle's Law 349
The Temperature-Volume Relationship: Charles's Law 350
The Quantity-Volume Relationship: Avogadro's Law 351
10.4 The Ideal-Gas Equation 352
Relationship Between the Ideal-Gas Equation and the Gas Laws 354
10.5 Further Applications of the Ideal-Gas Equation 357
Gas Densities and Molar Mass 357
Volumes of Gases in Chemical Reactions 359
10.6 Gas Mixtures and Partial Pressures 360
Partial Pressures and Mole Fractions 361
Collecting Gases Over Water 362
10.7 Kinetic-Molecular Theory 364
Application to the Gas Laws 366
10.8 Molecular Effusion and Diffusion 367
Graham's Law of Effusion 368 Diffusion and Mean Free Path 370
10.9 Real Gases: Deviations From Ideal Behavior 370
The van der Waals Equation 372
Summary and Key Terms 374
Exercises 375
1 1 Intermolecular Forces, Liquids, and Solids 383
11.1 A Molecular Comparison of Liquids and Solids 383
11.2 Intermolecular Forces 385
Ion-Dipole Forces 385
Dipole-Dipole Forces 386
London Dispersion Forces 386
Hydrogen Bonding 389
Comparing Intermolecular Forces 392
11.3 Some Properties of Liquids 393
Viscosity 394 Surface Tension 394
11.4 Phase Changes 394
Energy Changes Accompanying Phase Changes 395
Heating Curves 396
Critical Temperature and Pressure 398
11.5 Vapor Pressure 399
Explaining Vapor Pressure on the Molecular Level 399
Volatility, Vapor Pressure, and Temperature 400
Vapor Pressure and Boiling Point 401
11.6 Phase Diagrams 402
The Phase Diagrams of H z O and CO z 403
11.7 Structures of Solids 404
Unit Cells 405 The Crystal Structure of Sodium Chloride 406
Close Packing of Spheres 408
11.8 Bonding in Solids 411
Molecular Solids 411 Covalent-Network Solids 412 Ionic Solids 413
Metallic Solids 414
Summary and Key Terms 415
Exercises 416
1 2 Modern Materials 423
12.1 Liquid Crystals 423
Types of Liquid-Crystalline Phases 424
12.2 Polymers 428
Types of Polymers 432
Structures and Physical Properties of Polymers 432
Crosslinking Polymers 435
IX
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Contents
12.3 Ceramics 437
Processing of Ceramics 438 Ceramic Composites 439
Applications of Ceramics 440 Superconducting Ceramics 440
12.4 Thin Films 442
Uses of Thin Films 443
Formation of Thin Films 444
Summary and Key Terms 447
Exercises 447
1 3 Properties of Solutions 453
13.1 The Solution Process 453
Energy Changes and Solution Formation 454
Solution Formation, Spontaneity, and Disorder 456
Solution Formation and Chemical Reactions 457
13.2 Ways of Expressing Concentration 458
Mole Fraction, Molarity, and Molality 459
13.3 Saturated Solutions and Solubility 462
13.4 Factors Affecting Solubility 463
Solute-Solvent Interactions 463 Pressure Effects 465
Temperature Effects 467
13.5 Colligative Properties 469
Lowering the Vapor Pressure 469
Raoult's Law 470
Boiling-Point Elevation 472
Freezing-Point Depression 473
Osmosis 475
Determination of Molar Mass 476
13.6 Colloids 479
Hydrophilic and Hydrophobie Colloids 480
Removal of Colloidal Particles 481
Summary and Key Terms 483
Exercises 484
1 4 Chemical Kinetics 491
14.1 Reaction Rates 492
Rates in Terms of Concentrations 494
Reaction Rates and Stoichiometry 496
14.2 The Dependence of Rate on Concentration 497
Reaction Order 499
Units of Rate Constants 499
Using Initial Rates to Determine Rate Laws 500
14.3 The Change of Concentration with Time 501
First-Order Reactions 502
Half-life 504
Second-Order Reactions 505
14.4 Temperature and Rate 507
The Collision Model 507 Activation Energy 508
The Arrhenius Equation 511
14.5 Reaction Mechanisms 513
Elementary Steps 515
Rate Laws of Elementary Steps 516
Rate Laws of Multistep Mechanisms 518
Mechanisms with an Initial Fast Step 519
14.6 Catalysis 521
Homogeneous Catalysis 521
Heterogeneous Catalysis 522
Enzymes 524
Summary and Key Terms 529
Exercises 530
1 5 Chemical Equilibrium
539
15.1 The Concept of Equilibrium 540
15.2 The Equilibrium Constant 543
Expressing Equilibrium Constants in Terms of Pressure, K
The Magnitude of Equilibrium Constants 546
The Direction of the Chemical Equation and K 547
15.3 Heterogeneous Equilibria 548
15.4 Calculating Equilibrium Constants 550
Relating Kc and Kp 552
15.5 Applications of Equilibrium Constants 553
Predicting the Direction of Reaction 553
Calculation of Equilibrium Concentrations 554
15.6 Le Chätelier's Principle 557
Change in Reactant or Product Concentrations 557
Effects of Volume and Pressure Changes 558
Effect of Temperature Changes 560
The Effect of Catalysts 563
Summary and Key Terms 565
Exercises 566
1 6 Acid-Base Equilibria 573
16.1
16.2
16.3
16.4
16.5
Acids and Bases: A Brief Review 573
The Dissociation of Water 574
The Proton in Water 575
The pH Scale 576
Other "p" Scales 579 Measuring p H 579
Bronsted-Lowry Acids and Bases 580
Proton-Transfer Reactions 580
Conjugate Acid - Base Pairs 581
Relative Strengths of Acids and Bases 583
Strang Acids and Bases 585
Strong Acids 585
Strong Bases 586
16.6 Weak Acids 587
Calculating pH for Solutions of Weak Acids 590
Polyprotic Acids 594
16.7 Weak Bases 596
Types of Weak Bases 598
16.8 Relationship Between Ka and Kb 600
16.9 A c i d - B a s e Properties of Salt Solutions 603
16.10 A c i d - B a s e Behavior and Chemical Structure 605
Factors That Affect Acid Strength 605
Binary Hydrides 606
Oxyacids 606 Carboxylic Acids 609
16.11 Lewis Acids and Bases 611
Hydrolysis of Metal Ions 612
Summary and Key Terms 613
Exercises 614
546
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Contents
1 7 Additional Aspects of Equilibria 621
17.1 The Common-Ion Effect 621
17.2 Buffered Solutions 624
Composition and Action of Buffered Solutions 624
Buffer Capacity and pH 626
Addition of Strong Acids or Bases to Buffers 628
17.3 A c i d - B a s e Titrations 632
Strong Acid-Strong Base Titrations 632
The Addition of a Strong Base to a Weak Acid 634
Titration Curves for Weak Acids or Weak Bases 637
Titrations of Polyprotic Acids 640
17.4 Solubility Equilibria 641
The Solubility-Product Constant, Ksp 641
Solubility and Ksp 642
17.5 Factors that Äffect Solubility 644
Common-Ion Effect 644
Solubility and pH 646
Formation of Complex Ions 647 Amphoterism 650
17.6 Precipitation and Separation of Ions 651
Selective Precipitation of Ions 653
17.7 Qualitative Analysis for Metallic Elements 654
Summary and Key Terms 656
Exercises 657
1 8 Chemistry of the Environment 663
18.1 Earth's Atmosphere 663
Composition of the Atmosphere 664
18.2 The Outer Regions of the Atmosphere 666
Photodissociation 666
Photoionization 667
18.3 Ozone in the Upper Atmosphere 668
Depletion of the Ozone Layer 670
18.4 Chemistry of the Troposphere 672
Sulfur Compounds and Acid Rain 673
Carbon Monoxide 674
Nitrogen Oxides and Photochemical Smog 676
Water Vapor, Carbon Dioxide, and Climate 677
18.5 The World Ocean 679
Seawater 679
Desalination 680
18.6 Fresh Water 681
Dissolved Oxygen and Water Quality 682
Treatment of Municipal Water Supplies 684
Summary and Key Terms 685
Exercises 686
1 9 Chemical Thermodynamics 691
19.1 Spontaneous Processes 691
19.2 Entropy and the Second Law of Thermodynamics
Entropy 694
The Second Law of Thermodynamics
19.3 A Molecular Interpretation of Entropy 699
19.4 Calculation of Entropy Changes 703
19.5 Gibbs Free Energy 706
Standard Free-Energy Changes 707
19.6 Free Energy and Temperature 710
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Contents
19.7 Free Energy and the Equilibrium Constant
Summary and Key Terms 714
Exercises 715
711
2 0 Electrochemistry 723
20.1
20.2
Oxidation-Reduction Reactions 723
Balancing Oxidation-Reduction Equations 725
Half-Reactions 725
Balancing Equations by the Method of Half-Reactions 725
Balancing Equations for Reactions Occurring in Basic Solution 729
20.3 Voltaic Cells 730
20.4 Cell EMF 733
Standard Reduction Potentials 734
Oxidizing and Reducing Agents 738
20.5 Spontaneity of Redox Reactions 740
EMF and Free-Energy Change 742
20.6 Effect of Concentration on Cell EMF 743
The Nernst Equation 743
Equilibrium Constants for Redox Equations 745
20.7 Commercial Voltaic Cells 747
Lead Storage Battery 748
DryCell 749
Nickel - Cadmium Batteries 749
Fuel Cells 750
20.8 Electrolysis 750
Electrolysis of Aqueous Solutions 751
I Electrolysis with Active Electrodes 753
20.9 Quantitative Aspects of Electrolysis 754
Electrical Work 755
20.10 Corrosion 758
Corrosion of Iron 758
Prevention of Corrosion 759
Summary and Key Terms 761
Exercises 763
2 1 Nuclear Chemistry 771
21.1
21.2
21.3
21.4
21.5
21.6
21.7
21.8
Radioactivity 771
Nuclear Equations 772
Types of Radioactive Decay 773
Patterns of Nuclear Stability 774
Neutron-to-Proton Ratio 775
Radioactive Series 777
Further Observations 777
Nuclear Transmutations 779
Using Charged Particles 779 Using Neutrons 780
Transuranium Elements 780
Rates of Radioactive Decay 781
Dating 783 Calculations Based on Half-Life 784
Detection of Radioactivity 785
Radiotracers 786
Energy Changes in Nuclear Reactions 787
Nuclear Binding Energies 789
Nuclear Fission 791
Nuclear Reactors 792
Nuclear Fusion 795
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Contents
21.9 Biological Effects of Radiation 796
Radiation Doses 798 Radon 799
Summary and Key Terms 801
Exercises 802
2 2 Chemistry of the Nonmetals 807
22.1
General Concepts: Periodic Trends and Chemical Reactions 807
Chemical Reactions 809
22.2 Hydrogen 810
Isotopes of Hydrogen 811
Properties of Hydrogen 812
Preparation of Hydrogen 812
Uses of Hydrogen 813
Binary Hydrogen Compounds 814
22.3 Group 8A: The Noble Gases 815
Noble-Gas Compounds 815
22.4 Group 7A: The Halogens 817
Properties and Preparation of the Halogens 818
Uses of the Halogens 820
The Hydrogen Halides 820
Interhalogen Compounds 822
Oxyacids and Oxyanions 823
22.5 Oxygen 825
Properties of Oxygen 825
Preparation of Oxygen 825
Uses of Oxygen 826 Ozone 826
Oxides 828
Peroxides and Superoxides 829
22.6 The Other Group 6A Elements: S, Se, Te, and Po 830
General Characteristics of the Group 6A Elements 830
Occurrences and Preparation of Sulfur, Selenium, and Tellurium 831
Properties and Uses of Sulfur, Selenium, and Tellurium 832
Oxides, Oxyacids, and Oxyanions of Sulfur 833
Oxides, Oxyacids, and Oxyanions of Se and Te 835
Sulfides, Selenides, and Tellurides 835
22.7 Nitrogen 836
Properties of Nitrogen 836
Preparation and Uses of Nitrogen 837
Hydrogen Compounds of Nitrogen 837
Oxides and Oxyacids of Nitrogen 839
22.8 The Other Group 5A Elements: P, As, Sb, and Bi 841
General Characteristics of the Group 5A Elements 841
Occurrence, Isolation, and Properties of Phosphorus 843
Phosphorus Halides 843 Oxy Compounds of Phosphorus 844
Arsenic, Antimony, and Bismuth 847
22.9 Carbon 848
Elemental Forms of Carbon 848 Oxides of Carbon 850
Carbonic Acid and Carbonates 851
Carbides 852
Other Inorganic Compounds of Carbon 853
22.10 The Other Group 4A Elements: Si, Ge, Sn, and Pb 854
General Characteristics of the Group 4A Elements 854
Occurrence and Preparation of Silicon 855
Silicates 856
Glass 857
Silicones 859
22.11 Boron 859
Summary and Key Terms 860
Exercises 862
Contents
2 3 Metals and Metallurgy 869
23.1 Occurrence and Distribution of Metals
Minerals 870
Metallurgy 871
23.2 Pyrometallurgy 872
The Pyrometallurgy of Iron 873
Formation of Steel 875
23.3 Hydrometallurgy 875
The Hydrometallurgy of Aluminum 877
23.4 Electrometallurgy 877
Electrometallurgy of Sodium 878
Electrometallurgy of Aluminum 878
Electrorefining of Copper 879
869
23.5 Metallic Bonding 881
Physical Properties of Metals 882
Electron-Sea Model for Metallic Bonding 882
Molecular - Orbital Model for Metals 883
23.6 Alloys 886
Intermetallic Compounds 888
23.7 Transition Metals 888
Physical Properties 888
Electron Configurations and Oxidation States 890
23.8 Chemistry of Selected Transition Metals 892
Chromium 892
Iron 893 Copper 894
Summary and Key Terms 895
Exercises 896
Magnetism 891
2 4 Chemistry of Coordination Compounds
901
24.1 The Structure of Complexes 901
Charges, Coordination Numbers, and Geometries 902
24.2 Chelates 904
Metals and Chelates in Living Systems 906
24.3 Nomenclature 908
24.4 Isomerism 913
Structural Isomerism 913
Stereoisomerism 914
24.5 Color and Magnetism 916
Color 917
Magnetism 918
24.6 Crystal-Field Theory 919
Electron Configurations in Octahedral Complexes 924
Tetrahedral and Square-Planar Complexes 925
Summary and Key Terms 927
Exercises 928
2 5 The Chemistry of Life: Organic and Biological Chemistry 933
25.1 Introduction to Hydrocarbons 933
25.2 Alkanes 934
Structure of Alkanes 935
Structural Isomers 936
Nomenclature of Alkanes 936
Cycloalkanes 939
Reactions of Alkanes 941
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Contents
25.3 Unsaturated Hydrocarbons 941
Alkenes 941
Alkynes 943
Additional Reactions of Alkenes and Alkynes 944
Aromatic Hydrocarbons 946
25.4 Functional Groups: Alcohols and Ethers 947
Alcohols (R— OH) 948
Ethers (R—O—R') 950
25.5 Compounds with a Carbonyl Group 951
Aldehydes and Ketones 951
Carboxylic Acids 952
Esters 953
25.6 Introduction to Biochemistry 955
25.7 Proteins 956
Amino Acids 956
Polypeptides and Proteins 958
Protein Structure 960
25.8 Carbohydrates 962
Disaccharides 963 Polysaccharides 964
25.9 Nucleic Acids 966
Summary and Key Terms 969
Exercises 971
APPENDICES
A
Mathematical Operations
976
B
Properties of Water
C
Thermodynamic Quantities for Selected Substances at 298.15 K (25°C)
D
Aqueous-Equilibrium Constants
E
Standard Reduction Potentials at25°C
983
988
Answers to Selected Exercises A4
Glossary G-l
Photo/Art Credits C-l
Index 1-1
990
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