Master AP Chemistry 2nd Edition

Peterson’s

MASTER AP
CHEMISTRY
2nd Edition
Brett Barker


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Contents
...............................................................................
Before You Begin. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi

How This Book Is Organized. . . . . . . . . . . . . . . . . . . . . . . . . . . xi
Special Study Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii
Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii
You’re Well on Your Way to Success . . . . . . . . . . . . . . . . . . . xii
Give Us Your Feedback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xiii
Top 10 Strategies to Raise Your Score . . . . . . . . . . . . . . . . . . . xiv

PART I AP CHEMISTRY BASICS
1

All About the AP Chemistry Test. . . . . . . . . . . . . . . . . . .
Getting Started. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Preparing for the AP Chemistry Test . . . . . . . . . . . . . . . . . . . .
Making a Study Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What the Test Covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Getting to Know the Format of the Test . . . . . . . . . . . . . . . . .
How the AP Chemistry Test Is Scored . . . . . . . . . . . . . . . . . . .
Review of the AP Question Types . . . . . . . . . . . . . . . . . . . . . .
The Answer Sheets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3
3
3
4
5
9
10
11
18

24

PART II DIAGNOSING STRENGTHS AND
WEAKNESSES
2

Practice Test 1: Diagnostic . . . . . . . . . . . . . . . . . . . . . . . . . 29
Directions for Taking the Diagnostic Test . . . . . . . . . . . . . . . . 29
Answer Key . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

PART III AP CHEMISTRY REVIEW
3

Problem Solving and Measurement . . . . . . . . . . . . . . . 43
Defining Accuracy and Precision . . . . . . . . . . . . . . . . . . . . . . . 44
Using Significant Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Reviewing Scientific Notation . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Using Dimensional Analysis to Organize Your Work . . . . . . . 47
Laboratory Component. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52


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4

5

Atomic Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
The Historical Development of Modern Atomic Theory . . . . . . . . . . . . . . . .
Modern Atomic Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Periodic Table of the Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Quantum Model of the Atom. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Quantum Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electron Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Periodic Trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercises: Atomic Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

53
56
58
62
67
70
75
82
84
87

Nuclear Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
The Discovery of Radioactivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rutherford Discovers Different Types of Radiation . . . . . . . . . . . . . . . . . . . .
Different Types of Radioactive Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Radioactive Decay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Half-Life. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nuclear Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercises: Nuclear Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

89
90
90
93
94
101
103
106
109

6

Chemical Bonding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
Lewis Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112
Octet Rule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
Ionic Bonds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114
Covalent Bonds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
Using Lewis Structures to Determine Molecular Bonding . . . . . . . . . . . . . . . 117
Resonance Structures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
Intermolecular Forces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121
Exercises: Chemical Bonding. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

7

Molecular Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
VSEPR Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
Molecular Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130
Dipole Moments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
Valence Bond Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Sigma and Pi Bonds. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141
Molecular Orbital Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Exercises: Molecular Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149

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States of Matter—Gases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151
Units of Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Gas Laws. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
The Ideal Gas Law. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Gas Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dalton’s Law of Partial Pressures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Kinetic-Molecular Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Graham’s Law of Effusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Deviations from the Ideal Gas Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercises: States of Matter—Gases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9

151
153
156
157
159
161
164
166
169
172
176

States of Matter—Liquids and Solids . . . . . . . . . . . . . . . . . . . . . . . . . . 177
General Characteristics of Gases, Liquids, and Solids. . . . . . . . . . . . . . . . . . . 177
Energy and Phase Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Heating Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179
Vapor Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182
Phase Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
The Solid State. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188
Exercises: States of Matter—Liquids and Solids . . . . . . . . . . . . . . . . . . . . . . . 191
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196

10 Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

Measuring Concentration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198
Solvation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Colligative Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
Exercises: Solutions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221
11 Reaction Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Molecular Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
Chemical Equations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235
Major Reaction Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241
Ionic Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Oxidation-Reduction Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
Summary of the Main Reaction Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257
Exercises: Reaction Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263
Answers and Explanations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266

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12 Stoichiometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
The Mole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Determining Chemical Formulas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Calculations in Chemical Reactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Limiting Reactants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exercises: Stoichiometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

267
272
275
279
281
284
289

13 Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291
The Equilibrium Constant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
The Equilibrium Constant, Kc . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292
The Equilibrium Constant, Kp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293
The Relationship Between Kc and Kp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
The Reaction Quotient . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296
Solving Problems When Not All Equilibrium Concentrations Are Known . . 297
Le Châtelier’s Principle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Exercises: Equilibrium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314

14 Acids and Bases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
Definitions of Acids and Bases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315
The pH Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Weak Acids and Bases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Salt Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
The Relationship Between Ka and Kb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
The Common-Ion Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
Buffers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
Acid-Base Titrations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
Exercises: Acids and Bases. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 343
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
15 Additional Equilibrium Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 353
The Solubility-Product Constant, Ksp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
Solubility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354
The Ion Product . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356
Factors That Affect Solubility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
The Common-Ion Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358
The Effect of pH on Solubility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359
Complex Ions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361
Miscellaneous Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362
Coordination Complexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363
Nomenclature of Coordination Complexes . . . . . . . . . . . . . . . . . . . . . . . . . . . 364

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16 Kinetics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 379
Reaction Rate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380
Using Concentrations to Describe Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 381
Units and Rate Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 386
Determining Rate Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387
Reaction Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389
Half-Life. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391
The Relationship Between Temperature and Rate . . . . . . . . . . . . . . . . . . . . . 392
Reaction Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 395
Rate-Determining Steps and Rate Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397
The Effect of Catalysts on Reaction Rate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399
Exercises: Kinetics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410
17 Thermodynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411
The First Law of Thermodynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 412
Enthalpy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Thermochemical Equations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413
Hess’s Law . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417
Spontaneity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418
Entropy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419
The Second Law of Thermodynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 419
Gibbs Free Energy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421
Exercises: Thermodynamics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432
18 Electrochemistry. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433

Oxidation and Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433
Voltaic Cells . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434
The Relationship Between emf and Free Energy . . . . . . . . . . . . . . . . . . . . . . 439
The Nernst Equation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440
Electrolysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441
Faraday’s Laws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 444
Exercises: Electrochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457

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Exercises: Additional Equilibrium Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . 367
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 378


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Contents

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19 Organic Chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459
Alkanes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Isomers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Unsaturated Hydrocarbons. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Functional Groups. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Summing It Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

459
464
465
468
472

PART IV TWO PRACTICE TESTS
Practice Test 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477
Section I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 477
Section II Reference Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488
Section II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499
Practice Test 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521
Section I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521
Section II Reference Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532
Section II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538
Answer Key and Explanations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542

APPENDIX
College-by-College Guide to AP Credit and Placement . . . . . . . . . . . . 567

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Before You Begin
...............................................................................
HOW THIS BOOK IS ORGANIZED

Whether you have five months, nine weeks, or just four short weeks to
prepare for the test, Peterson’s Master AP Chemistry will help you develop a
study plan that caters to your individual needs and timetables. These
step-by-step plans are easy to follow and are remarkably effective.
•

Top 10 Strategies to Raise Your Score gives you tried and true
test-taking strategies.

•

Part I includes the basic information about the AP Chemistry Test
that you need to know.

•

Part II provides a diagnostic test to determine your strengths and
weaknesses. Use the diagnostic test as a tool to improve your
objective test-taking skills.

•

Part III provides reviews and strategies for answering the different
kinds of multiple-choice and free-response questions you will
encounter on the test. You will have numerous opportunities to
practice what you are learning in the Try It Out! quizzes and
exercises that follow the reviews. It is a good idea to read the answer
explanations to all of the questions, because you may find ideas or
tips that will help you better analyze the answers in the
practice tests.

•

Part IV includes two additional practice tests. Remember to apply
the test-taking system carefully, work the system to get more correct
responses, be careful of your time, and strive to answer more
questions in the time period.

•

The Appendix provides you with the new Peterson’s College-byCollege Guide to AP Credit and Placement (for more than 400
selective colleges and universities).

xi


xii

Before You Begin

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SPECIAL STUDY FEATURES
Peterson’s Master AP Chemistry was designed to be as user-friendly as it is complete. It
includes several features to make your preparation easier.

Overview
Each chapter begins with a bulleted overview listing the topics that will be covered in the
chapter. You know immediately where to look for a topic that you need to work on.

Summing It Up
Each strategy chapter ends with a point-by-point summary that captures the most important
points. The summaries are a convenient way to review the content of these strategy chapters.

Bonus Information
In addition, be sure too look in the page margins of your book for the following test-prep tools:
NOTE
Notes highlight critical information about the test.
TIP
Tips draw your attention to valuable concepts, advice, and shortcuts for tackling the test. By
reading the tips, you will learn how to approach different question types, pace yourself, and
remember what was discussed previously in the book.
ALERT!
Whenever you need to be careful of a common pitfall, you’ll find an Alert! This information
reveals and eliminates the misperceptions and wrong turns many people take on the test. By
taking full advantage of all features presented in Peterson’s Master AP Chemistry, you will
become much more comfortable with the test and considerably more confident about getting a
high score.

APPENDIX
Peterson’s College-by-College Guide to AP Credit and Placement gives you the equivalent
classes, scores, and credit awarded at more than 400 colleges and universities. Use this guide
to find your possible placement status, credit, and/or exemption based on your AP Chemistry
score.

YOU’RE WELL ON YOUR WAY TO SUCCESS
Remember that knowledge is power. You will be studying the most comprehensive guide
available, and you will become extremely knowledgeable about the test. We look forward to
helping you raise your score.

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Before You Begin

xiii

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Peterson’s, a Nelnet company, publishes a full line of resources to help guide you through the
college admission process. Peterson’s publications can be found at your local bookstore,
library, and high school guidance office, and you can access us online at www.petersons.com.
We welcome any comments or suggestions you may have about this publication and invite you
to complete our online survey at www.petersons.com/booksurvey. Or you can fill out the
survey at the back of this book, tear it out, and mail it to us at:
Publishing Department
Peterson’s
2000 Lenox Drive
Lawrenceville, NJ 08648
Your feedback will help us to provide personalized solutions for your educational
advancement.

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............................................................................................

GIVE US YOUR FEEDBACK

xiv

Before You Begin

.................................................................
............................................................................................

TOP 10 STRATEGIES TO RAISE YOUR SCORE
When it comes to taking an AP test, some test-taking skills will do you more good than
others. Here’s our pick for the top 10 strategies to raise your score:
1.

Pace yourself. Questions usually go from easiest to most difficult. Work as
quickly as you can through the beginning of the test. Don’t get lulled into a
false sense of security because you appear to be maintaining a good pace in the
first part.

2.

Educated guessing will boost your score. Although random guessing won’t
help you, anything better than random guessing will. You should be able to
make better-than-random guesses by using common sense and the process of
elimination techniques that are developed throughout this book.

3.

The easy answer isn’t always the best answer. Quite frequently, test
makers will put an attractive, but incorrect, answer as an (A) or (B) choice.
Reading all of the choices decreases your chance of being misled, particularly in
questions where no calculations are involved.

4.

Use common sense. On multiple-choice questions, it might be readily
apparent that you’ve made an error (e.g., none of the choices match your
answer). However, on the free response, there is no immediate feedback about
the accuracy of your answer. It is important to inspect your work to make sure
it makes sense.

5.

Put down your calculator. On the portions of the test where calculators are
prohibited, you should expect to deal with numbers that are fairly easy to work
with. However, you want to sharpen your skills for solving problems without a
calculator.

6.

Become familiar with a few properties of logarithms. There are several
formulas that require the use of logarithms. Because logarithms are easy to
work with on a calculator, you may never have learned much about them.
Becoming familiar with a few properties of logarithms can help you work more
quickly on some problems, especially pH problems.

7.

Make sure you fill in the bubble sheet neatly. Otherwise, the machine that
scores your answers won’t give you credit.

8.

Show all of your work on the free-response questions. If you only show
your answer, and it happens to be incorrect, the grader has no choice but to give
you no credit for the entire question. Writing down all of your steps makes sense.

9.

Know your stuff. You may not know every bit of information on the test, but
it is important that you remember the information you have learned.

10.

Be neat on the free-response questions. Let the grader focus on content,
rather than the form. The answers are not lengthy, so do your best to be neat
and organized.

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P ART I

.........................................................

AP CHEMISTRY BASICS

.....................................................................

CHAPTER 1

All About the

AP Chemistry Test



All About the AP
Chemistry Test
...............................................................................

•

Getting started

•

Preparing for the AP Chemistry Test

•

Making a study plan

•

What the test covers

•

Getting to know the format of the test

•

How the AP Chemistry Test is scored

•

Review of the AP question types

•

The answer sheets

•

Summing it up

GETTING STARTED
There is no question that the AP Chemistry Test is one of the most rigorous
tests offered by the College Board. Chances are, however, that if you are
planning to take the AP Chemistry Test, you are the type of student who is
ready to take on anything this test can dish out. You didn’t take AP Chem by
accident—you wanted to take it, and that’s because you are the type of
student who can handle challenges. So, although the test is difficult, don’t be
intimidated by it. You can beat this test!

PREPARING FOR THE AP CHEMISTRY TEST
Your first step is to understand that this test is not something to be taken
lightly. Top athletes spend a great deal of time preparing their bodies for big
competitions, and you, too, must prepare your mind for this test. But most
athletes don’t train by themselves. They work out with an experienced coach
who knows the keys to being successful. In preparation for the AP challenge,
you will need a coach to help you learn the best strategies for the test. Your

teacher should be your first coach. Due to the time constraints that
teachers face and the extensive amount of material covered in this course, you
3

chapter 1

OVERVIEW


4

PART 1: AP Chemistry Basics

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will also need an assistant coach to help you prepare. This book can be that assistant coach,
but it is not designed to replace your teacher. He or she knows the course, the material, and
you, but unless your teacher can move in with you while you are preparing for the test, he or
she can’t provide you with all of the tools you will need to succeed. There aren’t enough hours
in the school day to teach you everything you need to know for the test. This book can be your
personal tutor. The material between its covers will help to familiarize you with all of the
material covered on the test, the structure of the test, and strategies to prepare for and to take
the test and it can provide you with instant feedback about your performance. This book is
also designed with the understanding that your time is valuable! You most likely have a very
busy schedule before and after school, and the last thing you need is to add another
time-consuming activity. Some of the information that you may have learned or that is in your
textbook may go beyond the level of the AP test. On other subjects, you may have learned less
information than you need. This book attempts to get right to the point and to only review the
material that you will need to know for the test.

MAKING A STUDY PLAN
The fact that you bought this book is a step in the right direction for your success on the AP
Chemistry Test. And there are some strategies that will help you get the most out of it. The
following are two key questions you need to answer before you proceed:
How much time do I have before the AP test?
How much time can I realistically devote to test preparation?

Your answers to these questions will help you to set a pace for your review. If you have a long
time before the test (two or three months), you can set a fairly relaxed pace. If you have a short
time (one month or less), your pace will be more rigorous. Either way, the book is designed to
be flexible and to accommodate a variety of situations. What follows is a brief description of the
remainder of the book and how you can use it under different circumstances.
Read this section, and then go on to Chapter 3. These chapters contain vital information
about the AP test that will help you to develop sound test-taking strategies. Once finished,
take the diagnostic test. Before you take it, however, you need to understand that the
diagnostic test is not a practice AP test! This book has two full-length practice AP tests, but
they do not appear until Part IV of the book. The diagnostic test is designed to resemble the
approximate difficulty level of the AP test and to reflect the content on the test, but there are
some significant differences in the structures of the two. The purpose of the test is to help you
identify strengths and potential weaknesses, which you’ll need to know to design your
personal study plan. Once you finish the diagnostic test, use these suggested guidelines to
complete your test preparations.

The Complete Course
If you have plenty of time before the test (two or three months), it is recommended that you
complete the entire course. There are nineteen chapters, so if you divide these up over a
two-month period, you would need to complete about two chapters a week. If you have a
three-month period, this drops down to about one chapter every five or six days. You will
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Chapter 1: All About the AP Chemistry Test

5

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The Accelerated Course
If you are running out of time, you’ll need to design an ambush approach to your studies. Don’t
attempt to complete the entire book. From the diagnostic test, select your weakest areas and
plan to go through those first. Make a list of the topics you feel you can reasonably work
through before the test. Be very careful during this process. Do not skip sections you know very
little about, figuring, “Oh, that probably won’t be on the test.” If it is on the content outline, it
will be on the test! And, if you are especially unfortunate, the section you skip could end up as
one of the mandatory essay questions. Even if you don’t have time for all of the practice
problems in a section, get through what you can. If you know certain topics very well, skip
them. It’s not ideal, but if you are reading this section (for the accelerated course) it is probably
because you don’t have time to do everything. Just remember, though, that every chapter you
can work through is a bonus for you. Rather than be discouraged about not having enough time
to finish everything, be encouraged about the sections you will finish. These are areas you
wouldn’t have known or would have done poorly on without your extra effort. Be positive!

WHAT THE TEST COVERS
Each year, the College Board provides a content outline for the AP Chemistry course as well
as a breakdown of the approximate percentage of the AP test that will deal with certain
topics. What follows is an outline of the content of the most recent test.

Structure of Matter (20 percent)
•

•

Atomic theory and atomic structure
•

Evidence for the atomic theory

•

Atomic masses; determination by chemical and physical means

•

Atomic number and mass number; isotopes

•

Electron energy levels: atomic spectra, quantum numbers, atomic orbitals

•

Periodic relationships, such as atomic radii, ionization energies, electron affinities,
and oxidation states

Chemical bonding
•

Binding forces
•

Types: ionic, covalent, metallic, hydrogen bonding, van der Waals theory
(including London dispersion forces)

•

Relationships to states, structure, and properties of matter

•

Polarity of bonds, electronegativities
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receive the maximum benefit if you can complete the entire book. Even if you are planning to
complete the entire book, it is recommended that you pick the most difficult areas first,
especially those that you may not have covered much (or at all) in class. This way, if
something happens and you don’t have as much time as you thought, you’ve at least gone
through the sections that will benefit you the most.


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PART 1: AP Chemistry Basics

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•

•

•

Molecular models
•

Lewis structures

•

Valence bond: hybridization of orbitals, resonance, and sigma and pi bonds

•

VSEPR

Geometry of molecules and ions, structural isomerism of simple organic molecules
and coordination complexes; dipole moments of molecules; relation of properties to
structure

Nuclear chemistry: nuclear equations, half-lives, and radioactivity; chemical applications

States of Matter (20 percent)
•

•

•

Gases
•

•

Laws of ideal gases
•

Equation of state for an ideal gas

•

Partial pressures

Kinetic-molecular theory
•

Interpretation of ideal gas laws on the basis of this theory

•

Avogadro’s hypothesis and the mole concept

•

Dependence of kinetic energy of molecules on temperature

•

Deviations from ideal gas laws

Liquids and solids
•

Liquids and solids from the kinetic-molecular viewpoint

•

Phase diagrams of one-component systems

•

Changes of state, including critical points and triple points

•

Structure of solids; lattice energies

Solutions
•

Types of solutions and factors affecting solubility

•

Methods of expressing concentration (The use of normalities is not tested.)

•

Raoult’s law and colligative properties (nonvolatile solutes); osmosis

•

Nonideal behavior (qualitative aspects)

Reactions (35–40 percent)
•

Reaction types
•

Acid-base reactions; concepts of Arrhenius, Brønsted-Lowry, and Lewis; coordination complexes; amphoterism

•

Precipitation reactions

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Chapter 1: All About the AP Chemistry Test

7

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•

•

•

•

Oxidation-reduction reactions
•

Oxidation number

•

The role of the electron in oxidation-reduction

•

Electrochemistry: electrolytic and galvanic cells; Faraday’s laws; standard halfcell potentials; Nernst equation; prediction of the direction of redox reactions

Stoichiometry
•

Ionic and molecular species present in chemical systems: net ionic equations

•

Balancing of equations, including those for redox reactions

•

Mass and volume relations with emphasis on the mole concept, including empirical

formulas and limiting reactants

Equilibrium
•

Concept of dynamic equilibrium, physical and chemical; Le Châtelier’s Principle;
equilibrium constants

•

Quantitative treatment
•

Equilibrium constants for gaseous reactions: KP, K

•

Equilibrium constants for reactions in solution
•

Constants for acids and bases: pK; pH

•

Solubility product constants and their application to precipitation and the
dissolution of slightly soluble compounds

•

Common ion effect; buffers; hydrolysis

Kinetics
•

Concept of rate of reaction

•

Use of experimental data and graphical analysis to determine reactant order, rate
constants, and reaction rate laws

•

Effect of temperature change on rates

•

Energy of activation; the role of catalysts

•

The relationship between the rate-determining step and a mechanism

Thermodynamics
•

State functions

•

First law: change in enthalpy; heat of formation; heat of reaction; Hess’s law; heats
of vaporization and fusion; calorimetry

•

Second law: entropy; free energy of formation; free energy of reaction; dependence
of change in free energy on enthalpy and entropy changes

•

Relationship of change in free energy to equilibrium constants and electrode potentials

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•


8

PART 1: AP Chemistry Basics

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Descriptive Chemistry (10–15 percent)
•

Chemical reactivity and products of chemical reactions

•

Relationships in the periodic table: horizontal, vertical, and diagonal with examples from
alkali metals, alkaline earth metals, halogens, and the first series of transition elements

•

Introduction to organic chemistry: hydrocarbons and functional groups (structure,
nomenclature, chemical properties). Physical and chemical properties of simple organic
compounds should also be included as exemplary material for the study of other areas
such as bonding, equilibria involving weak acids, kinetics, colligative properties, and
stoichiometric determinations of empirical and molecular formulas.

Laboratory (5–10 percent)
These questions are based on common laboratory procedures that should have been learned
as part of the course, such as:
•

making observations of chemical reactions and substances

•

recording data

•

calculating and interpreting results based on the quantitative data obtained

•

effectively communicating the results of experimental work

Students should be able to solve specific types of chemical calculations. The types of problems
that might possibly be included on the test include:
•

Percentage composition

•

Empirical and molecular formulas from experimental data

•

Molar masses from gas density, freezing-point, and boiling-point measurements

•

Gas laws, including the ideal gas law, Dalton’s law, and Graham’s law

•

Stoichiometric relations using the concept of the mole; titration calculations

•

Mole fractions; molar and molal solutions

•

Faraday’s laws of electrolysis

•

Equilibrium constants and their applications, including their use for simultaneous
equilibria

•

Standard electrode potentials and their use; Nernst equation

•

Thermodynamic and thermochemical calculations

•

Kinetics calculations

This may feel like too much information for you to ever master, and it is very rare that any
teacher could make it through all of the recommended topics and activities within an
academic year. In the next section, we will look at some details about how you’ll be asked to
apply your knowledge of the topics above, which should help to ease some of your fears.

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Chapter 1: All About the AP Chemistry Test

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The College Board reserves the right to make changes to the test as it chooses; however, the
structure of the test has undergone only very slight changes in the years it’s been offered. To
keep abreast of the specific details about the AP Chemistry Test, refer to the College Board
Web site at />The test is 185 minutes long and is divided into two sections. The first part, Section I, consists
of 75 multiple-choice questions. There is a 90-minute time limit on Section I, and the results
make up 50 percent of the total grade. The second part, Section II, is the Free-Response
section. It is 95 minutes long, makes up 50 percent of the total grade, and is broken into two
sections. The first section, Part A, is 55 minutes long; you may use calculators during this
portion, but this is the only part of the test on which you can use a calculator! It consists of
three problems—the frist question will be based on equilibrium, but the other two questions
may be based on any topic. These problems are calculation-based and are multipart problems.
After 55 minutes, you will be instructed to put your calculator away and proceed to the second
portion of Section II, Part B.
Part B is divided into three mandatory subsections. The first is a list of three chemical
equations. In this subsection, you are provided with a written description of the reactants and
conditions of a reaction, from which you must determine the product(s). Each reaction must
have a balanced net ionic equation, with the lowest whole numbers for the ratios, and you
must answer a question about the reaction (e.g.—which reactant is oxidizing). You must also
convert the entire equation into symbolic form (substituting symbols for written descriptions).
The second subsection in Part B consists of two multipart questions, one of which may be a
laboratory-based question. The content of these questions varies (later in this chapter you
will see a list of previous topics). All of these parts of the AP test are summarized in the
table below:
Section I: Multiple Choice. 75 questions. 90 minutes. 50 percent of total grade
Section II: Free Response. 6 questions. 95 minutes. 50 percent of total grade.
Breakdown of the Free-Response Section

Part A
55 Minutes
(with calculator—only calculators without
alphabetic keyboards)

60 percent of Section II Score
(30 percent of entire test)

Equilibrium problem

20 percent (10 percent overall)

Other problem*

20 percent (10 percent overall)

Other problem*

20 percent (10 percent overall)

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GETTING TO KNOW THE FORMAT OF THE TEST


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PART 1: AP Chemistry Basics

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Breakdown of the Free-Response Section
Part B

40 Minutes
(no calculator)

40 percent of
Section II Score
(20 percent of entire test)

Reactions question (3 required)

10 percent (5 percent overall)

Essay question*

15 percent (7.5 percent overall)

Essay question*

15 percent (7.5 percent overall)

* One of the other problems or essays will be based on laboratory topics.

HOW THE AP CHEMISTRY TEST IS SCORED
Multiple Choice

On the multiple-choice portion of the test, there are 75 questions. Scores are determined
according to the following formula:
Score 5 Correct Score 2 0.25(Incorrect Score)

The reason for the strange equation is to prevent wild guessing. Take, for example, a student
who bubbled in the same letter for every question. To be safe, she chooses “C” because it is in
the middle of the five choices. On a test of 75 questions, with five possible responses (A2E) for
each question, chances are that 15 of them will actually be C (15 will also be A, 15 will be B,
etc.). That means that the student will have gotten 15 problems correct and 60 incorrect.
Plugging these numbers into the equation will give you:
Score 5 Correct Score 2 0.25(Incorrect Score) 5 15 2 0.25(60) 5 15 2 15 5 0

As you can see, this individual could have left all of the answers blank and still gotten the
same score. There is no benefit to wild guessing. In Chapter 2, you will learn some techniques
to take the “wild” out of guessing.

Free Response
The free-response questions are graded by a group of more than 100 AP Chemistry teachers
and college chemistry professors who gather at the beginning of the summer to grade all of
the tests. Scoring rubrics are carefully designed for each question, and the graders spend the
week grading the tests in a very thorough, unbiased manner. The key to your success on the
free-response questions is your ability to write to these rubrics. While there is no way to
predict in advance what topics will be covered in the free-response section (even though many
people try), there are some strategies that will improve your chances. Hopefully, your teacher
has had you practice writing AP-style essays, but even if he has not, you will still have an
opportunity to try some in this book. You will also be able to evaluate your own performance
using scoring rubrics that are similar to those used by the AP graders. This exercise will help
you sharpen your writing skills and maximize your chances for a high score.
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Chapter 1: All About the AP Chemistry Test

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Once your multiple-choice and free-response scores have been calculated, each score will be
used to calculate your composite score. This score ranges from 0 to 5, according to the scale
shown below. Note the percentage of students receiving each score:
AP Grade

Qualification

Percent of students earning
this score (from 1999 test)

5

Extremely well qualified

17.2

4

Well qualified

14.7

3

Qualified

25.3

2

Possibly qualified

22.0

1

No recommendation

20.8

One thing these numbers don’t tell you is what it takes to get a 5 or a 4. The number of points
to achieve these grades will differ slightly from year to year, but they remain relatively
consistent over time. The Chemistry test is intentionally made so that a score of 100 percent
is extremely unlikely. In most administrations, scores of 50260 percent usually receive scores
of 5.

REVIEW OF THE AP QUESTION TYPES
Now that you’ve had a chance to get a general feel for the test, let’s begin to take a closer look
at the test’s design. There are certain types of questions that appear on the AP Chemistry
Test. Becoming aware of these types of questions, as well as learning some strategies to
answer them, can help you become more confident when you take the test.
The main advantage of the multiple-choice section is that there are five answers to choose
from, and the correct answer is always given to you! Properly written multiple-choice
questions should not be easy to answer, however. Despite the fact that the correct answers are

found somewhere in the five choices, the correct answer will be imbedded among what are
known as distracters. Distracters are choices that are close to being correct but that are not
the correct answer. The main difficulty comes from the amount of time you’re given on this
section. There are 75 questions to complete in 90 minutes. That’s an average of 1 minute and
12 seconds per question—and without the benefit of a calculator! For those of you who spent
long evenings working on problem sets that only had a handful of problems in them, this may
have you concerned. Take heart, though, because there are some tricks you can learn to save
you time, especially since you have the correct answers in front of you. So, one portion of this
chapter is devoted to learning typical formats for multiple-choice questions on the chemistry
test and how best to approach each to save time and improve your performance.
The main difficulty of the free-response section is that the answers are not provided for you.
You have the benefit of more time (and on part A, you can use a calculator), but you’re on your
own for coming up with a solution. For the free-response questions, it is important to become
familiar with the scoring rubrics. Knowing how your answers will be graded can help you
answer questions more efficiently and with a higher probability of earning points. Later in
this chapter we will look at some strategies for writing effective free-response answers.

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YOUR COMPOSITE SCORE