Discovering Design With Chemistry Preliminary Table of Contents Chapter 1: Measuring Up... 1 Introduction... 1 Measuring Distance... 1 Using Different Units... 2 Significant Figures... 4 Using Significant Figures in Mathematical Problems... 6 A Relationship Between Units... 8 Experiment 1.1: Determining the Relationship Between in and cm... 8 Converting Between Units... 9 Prefixes in the Metric System... 11 Scientific Notation... 13 Measuring Area and Volume: Derived Units... 15 Experiment 1.2: Determining the Relationship Between cm 3 and ml... 17 Converting Between Volume Units... 18 Measuring Mass... 19 Measuring Time... 22 Density... 22 More on Density... 25 Experiment 1.3: Density... 25 Solutions to the Comprehension Check Questions... 27 Sample Calculations for Experiment 1.1... 32 Sample Calculations for Experiment 1.2... 32 Sample Calculations for Experiment 1.3... 33 Review... 34 Chapter 2: What s The Matter?... 37 Introduction... 37 Mixtures and Pure Substances... 37 Experiment 2.1: Separating a Mixture of Salt and Chervil... 38 Homogeneous and Heterogeneous Mixtures... 40 Mass Conservation: It s Not Just a Good Idea, It s the Law!... 42 Experiment 2.2: The Conservation of Mass... 42 Elements and Compounds... 44 The Law of Definite Proportions... 47 Experiment 2.3: Oh What a Difference Some Oxygen Makes... 47 Dalton s Atomic Theory... 51 The Law of Multiple Proportions... 53 What s Wrong with Dalton s Theory: Part One... 54 What s Wrong with Dalton s Theory: Part Two... 58 Solutions to the Comprehension Check Questions... 61 Review... 64
Chapter 3: Making Sense of Atoms and Elements... 67 Introduction... 67 Abbreviating and Arranging Elements... 67 Defining the Atoms that Make Up an Element... 70 Isotopes, Radiation, and Nuclear Weapons... 73 Light Waves... 75 The Electromagnetic Spectrum... 78 Experiment 3.1: The Wavelength of Microwaves... 79 The Energy of Light... 81 Illuminating the Structure of Atoms: The Bohr Model... 82 Experiment 3.2: Flame Tests... 83 More on The Bohr Model... 87 Spectroscopy... 89 Solutions to the Comprehension Check Questions... 91 Sample Calculations for Experiment 3.1... 94 Review... 95 Chapter 4: The Modern View of Atoms and Their Chemistry... 97 Introduction... 97 Waves, Particles, or Both?... 97 Experiment 4.1: Interfering Light... 97 Out with Orbits, In with Orbitals... 100 Wait a Minute Do Electrons Really Behave Like Waves?... 104 So Where Do You Put These Electrons?... 105 What Good Are Electron Configurations?... 108 Lewis Structures for Elements... 110 Metals, Nonmetals, and the In-Betweens... 112 Experiment 4.2: Comparing a Metal and a Nonmetal... 112 Ionic Compounds... 114 Ionic Compounds that Don t Follow the Rules... 117 An Important Characteristic of Ionic Compounds... 119 Experiment 4.3: Electrolytes and Nonelectrolytes... 119 Solutions to the Comprehension Check Questions... 122 Review... 125 ii
Chapter 5: Covalent Compounds and Their Molecular Geometry... 127 Introduction... 127 Share and Share Alike... 127 Lewis Structures of Covalent Compounds... 129 More Complicated Lewis Structures... 131 Naming Covalent Compounds... 134 Periodic Properties and How They Affect Covalent Compounds... 136 A Consequence of Polar Covalent Bonds... 139 Experiment 5.1: Bending Water... 140 Molecules in Three Dimensions... 143 Is It Polar?... 148 Why Is Polarity Important?... 151 Experiment 5.2: Polar and Nonpolar... 151 Solutions to the Comprehension Check Questions... 154 Review... 159 Chapter 6: Physical and Chemical Change... 161 Introduction... 161 Chemical and Physical Changes... 161 Temperature Changes... 162 Phase Changes... 164 Experiment 6.1: Cool it!... 165 The Kinetic Theory of Matter... 167 Experiment 6.2: In Between and All Around... 167 An Important Exception: Water... 171 Chemical Reactions... 172 Balancing Chemical Equations... 176 The Mathematical Nature of Chemical Equations... 180 Formation and Decomposition Reactions... 181 Single and Double Displacement Reactions... 183 Experiment 6.3: Copper-Plated Nails... 183 Combustion Reactions... 185 Experiment 6.4: Burning Iron... 185 Solutions to the Comprehension Check Questions... 189 Review... 195 iii
Chapter 7: Stoichiometry... 197 Introduction... 197 Counting Atoms... 197 Mole Problems Not Just in Your Backyard... 199 Using the Mole Concept... 201 Experiment 7.1: How Wet Is Hydrated Copper Sulfate?... 202 Moles Infesting Chemical Equations... 204 There is a Limit!... 206 Experiment 7.2: The Limiting Reactant... 206 Using More Complicated Chemical Equations... 209 Stoichiometry Gets Massive... 212 Experiment 7.3: The Amount of NaHCO3 in Alka-Seltzer... 216 Solutions to the Comprehension Check Questions... 219 Sample Calculations for Experiment 7.1... 223 Sample Calculations for Experiment 7.3... 223 Review... 224 Chapter 8: Still More on Stoichiometry... 227 Introduction... 227 To Err is Human... 227 Experiment 8.1: Percent Yield... 227 Percent Yield... 230 Empirical and Molecular Formulas... 232 Determining Empirical Formulas of Metal Oxides... 235 Determining Empirical Formulas With Combustion Analysis... 237 More complicated Combustion Analysis... 239 Determining Empirical Formulas from Percent Composition... 241 Polyatomic Ions... 243 Solutions to the Comprehension Check Questions... 248 Sample Calculations for Experiment 8.1... 253 Review... 254 iv
Chapter 9: Chemists Have Solutions... 257 Introduction... 257 Dissolving Solutes into Solvents... 257 Solubility... 260 Experiment 9.1: Temperature and Solubility... 260 Some Ionic and Polar Covalent Chemicals Aren t Very Soluble... 263 Experiment 9.2: Forming a Precipitate... 264 Concentration... 266 Experiment 9.3: The Importance of Concentration... 266 Molarity... 269 Using Molarity in Stoichiometry... 270 Molality: Another Unit for Concentration... 272 This is Depressing!... 274 Experiment 9.4: Freezing Point Depression... 274 From Depressing to Elevating... 275 Solutions to the Comprehension Check Questions... 280 Review... 286 Chapter 10: It s a Gas!... 289 Introduction... 289 How Pressure is Defined... 289 Boyle s Law... 291 Experiment 10.1: Boyle s Law... 292 Charles s Law... 294 Experiment 10.2: Charles s Law... 294 Charles s Law and Absolute Temperature... 295 The Combined Gas Law... 298 It s Got To Be Ideal!... 300 This Law Is Ideal!... 301 Gases in Stoichiometry... 304 Dalton s Law of Partial Pressures... 306 Vapor Pressure and Boiling Point... 310 Experiment 10.3: Boiling Water with Ice... 312 Vapor Pressure and Dalton s Law... 313 Experiment 10.4: The Concentration of Hydrogen Peroxide... 314 Solutions to the Comprehension Check Questions... 317 Sample Calculations for Experiment 10.4... 322 Review... 323 v
Chapter 11: Some Pretty Basic (and Acidic) Chemicals... 325 Introduction... 325 Characteristics of Acids and Bases... 325 Experiment 11.1: Litmus Tests... 327 The Chemical Definition of Acids and Bases... 329 Acids and Ionic Bases... 332 Sometimes, You Can Just Tell... 333 Determining The Chemical Equation for an Acid/Base Reaction... 335 The ph Scale... 337 Experiment 11.2: Anthocyanins as Acid/Base Indicators... 339 Acid/Base Neutralization... 341 Acid/Base Titrations... 343 Experiment 11.3: The Percent of Acetic Acid in Vinegar... 345 Diluting Acid and Bases... 327 Solutions to the Comprehension Check Questions... 349 Sample Calculations for Experiment 11.3... 353 Review... 354 Chapter 12: Reduction and Oxidation... 357 Introduction... 357 Oxidation States... 357 Determining Oxidation States... 360 Reduction and Oxidation... 363 Experiment 12.1: Oxidation States of Iron... 366 The Basics of Batteries... 368 Experiment 12.2: A Simple Galvanic Cell... 368 Analyzing Galvanic Cells... 372 Counting Electrons and Balancing Simple Redox Equations... 374 Batteries That You Actually Use... 376 Electroplating... 378 Experiment 12.3: Electroplating... 378 The Downside of Redox Reaction... 380 Solutions to the Comprehension Check Questions... 381 Review... 385 vi
Chapter 13: The Heat is On... 387 Introduction... 387 What is Heat?... 387 Calories, calories, and Joules... 389 Specific Heat Capacity... 391 Experiment 13.1: Specific Heat Capacity... 391 Measuring Heat... 393 Calorimetry... 395 Experiment 13.2: A Calorimetry Experiment... 397 More Detailed Calorimetry Experiments... 400 Latent Heat... 402 Experiment 13.3: Melting Ice... 403 The Heat Associated with Chemical Reactions... 406 Experiment 13.4: An Endothermic Reaction... 407 Solutions to the Comprehension Check Questions... 409 Sample Calculations for Experiment 13.2... 414 Review... 415 Chapter 14: Thermodynamics... 417 Introduction... 417 Enthalpy... 417 Experiment 14.1: Measuring H... 418 Enthalpy Change and Bond Energies... 419 Enthalpy Change and Hess s Law... 422 Enthalpy and Stoichiometry... 426 Activation Energy... 427 Thermodynamics... 430 Changes in Entropy... 434 Getting Numbers for S... 437 The Gibbs Free Energy... 439 Experiment 14.2: Determining S for a Physical Change... 442 The Gibbs Free Energy and Hess s Law... 443 Solutions to the Comprehension Check Questions... 446 Sample Calculations for Experiment 14.1... 450 Review... 451 vii
Chapter 15: Kinetics... 453 Introduction... 453 Rate Your Reactions... 454 What Things Affect the Rate of a Chemical Reaction?... 455 Experiment 15.1: Changing the Rate of a Reaction... 456 Collision Theory... 457 The Rate Equation... 459 It Lasts Only for an Instant... 461 Determining Reaction Orders... 462 Activation Energy, Temperature, and the Rate Constant... 467 Catalysts... 469 Experiment 15.2: Catalysts Don t Get Used Up... 469 How Catalysts Work... 471 Solutions to the Comprehension Check Questions... 476 Review... 481 Chapter 16: Chemical Equilibrium... 483 Introduction... 483 Establishing Chemical Equilibrium... 484 Experiment 16.1: Water in Equilibrium... 484 The Equilibrium Constant... 486 The Chemical Meaning of the Equilibrium Constant... 488 Ignoring Things... 490 Are We There Yet?... 492 Why Salt Melts Ice... 494 This is Disturbing... 495 More on Le Chatelier s Principle... 497 Experiment 16.2: Le Chatelier s Principle and Concentration... 497 Le Chatelier s Principle and Temperature... 500 Experiment 16.3: Le Chatelier s Principle and Temperature... 501 Le Chatelier s Principle and Pressure... 503 Equilibrium Concepts Applied to Acids and Bases... 504 All Good Things Must Come to an End... 507 Solutions to the Comprehension Check Questions... 508 Review... 511 viii