C ontents Preface i chaPter 1 an introduction to chemistry 3 New 1.1 An Introduction to Chemistry 3 Observation oarbes emrvaadteio.ns Collection of ian tfeosrtmabaltei ohny pleoatdhse stios . This seu bhjyepcotetdh etsois Disproof 1.2 Suggestions for Studying Chemistry 5 Hypothesis experimentation. The experiment fails. Further research is done to Experimentation refine the applications. 1.3 The Scientific Method 7 Application Successful results are published. Applications are sought. 1.4 Measurement and Units 9 Publication The experiment Confirmation The experiment iws irtehpoeuatt esdu ccess. is repeated successfully. 1.5 Reporting Values from Measurements 20 chaPter 2 the structure of matter and the chemical elements 33 2.1 Solids, Liquids, and Gases 34 Metalloids 2.2 The Chemical Elements 38 B Si Nonmetals 2.3 The Periodic Table of the Elements 42 Ge As Sb Te Metals Po At 2.4 The Structure of the Elements 46 2.5 Common Elements 53 chaPter 3 chemical comPounds 69 3.1 Classification of Matter 70 3.2 Compounds and Chemical Bonds 73 3.3 Molecular Compounds 79 500 400 300 3.4 Naming Binary Covalent Compounds 90 200 100 3.5 Ionic Compounds 94 chaPter 4 an introduction to chemical reactions 125 4.1 Chemical Reactions and Chemical Equations 126 4.2 Solubility of Ionic Compounds and Precipitation Reactions 133 chaPter 5 acids, Bases, and acid-Base reactions 159 This proton, H(cid:11), is transferred to a water molecule. 5.1 Acids 160 (cid:13) (cid:11) (cid:11) (cid:11) 5.2 Acid Nomenclature 168 HCl(g) (cid:11) H2O(l) Cl(cid:13)(aq) (cid:11) H3O(cid:11)(aq) 5.3 Summary of Chemical Nomenclature 171 5.4 Strong and Weak Bases 173 5.5 pH and Acidic and Basic Solutions 178 5.6 Arrhenius Acid-Base Reactions 180 5.7 Brønsted-Lowry Acids and Bases 188 chaPter 6 oxidation-reduction reactions 207 6.1 An Introduction to Oxidation-Reduction Reactions 208 6.2 Oxidation Numbers 213 e(cid:13) e(cid:13) 6.3 Types of Chemical Reactions 218 Neleecgtartoidvee Zn ((cid:13)) KNO3 SBarlitd ge((cid:11)) Cu Peloescittrioved e (anode) (cathode) 6.4 Voltaic Cells 224 SO42(cid:13) Cu2(cid:11) Zn2(cid:11) NO3(cid:13) K(cid:11) SO42(cid:13) chaPter 7 energy and chemical reactions 249 Electrolyte Site of Oxidation Site of Reduction Zn Zn2+ + 2e– Cu2+ + 2e– Cu 7.1 Energy 250 7.2 Chemical Changes and Energy 263 7.3 Ozone: Pollutant and Protector 266 7.4 Chlorofluorcarbons: A Chemical Success Story Gone Wrong 270 chaPter 8 unit conversions 287 8.1 Unit Analysis 288 8.2 Rounding and Significant Figures 293 8.3 Density and Density Calculations 301 8.4 Percentage and Percentage Calculations 306 8.5 A Summary of the Unit Analysis Process 308 8.6 Temperature Conversions 312 chaPter 9 chemical calculations and chemical formulas 329 9.1 A Typical Problem 330 9.2 Relating Mass to Number of Particles 331 9.3 Molar Mass and Chemical Compounds 337 9.4 Relationships Between Masses of Elements and Compounds 342 9.5 Determination of Empirical and Molecular Formulas 346 chaPter 10 chemical calculations and chemical equations 367 10.1 Equation Stoichiometry 368 10.2 Real-World Applications of Equation Stoichiometry 376 10.3 Molarity and Equation Stoichiometry 385 chaPter 11 modern atomic theory 413 2p 2p z y 11.1 The Mysterious Electron 414 2p x 11.2 Multi-Electron Atoms 424 chaPter 12 molecular structure 447 12.1 A New Look at Molecules and the Formation of Covalent Bonds 448 12.2 Drawing Lewis Structures 455 12.3 Resonance 465 12.4 Molecular Geometry from Lewis Structures 467 chaPter 13 gases 483 Movable piston 13.1 Gases and Their Properties 484 Valve to add and remove gas Thermometer 13.2 Ideal Gas Calculations 494 Pressure gauge 13.3 Equation Stoichiometry and Ideal Gases 502 13.4 Dalton’s Law of Partial Pressures 509 chaPter 14 liquids: condensation, evaPoration, and dynamic equiliBrium 533 14.1 Changing from Gas to Liquid and from Liquid to Gas—An Introduction to Dynamic Equilibrium 534 (cid:68)(cid:11) (cid:68)(cid:13) (cid:68)(cid:13) 14.2 Boiling Liquids 542 (cid:68)(cid:13) (cid:68)(cid:11) (cid:68)(cid:13) (cid:68)(cid:11) (cid:68)(cid:11) 14.3 Particle-Particle Attractions 547 (cid:68)(cid:11) (cid:68)(cid:13) (cid:68)(cid:11)(cid:68)(cid:13) (cid:68)(cid:13)(cid:68)(cid:11)(cid:68)(cid:13) (cid:68)(cid:11) (cid:68)(cid:11) (cid:21)(cid:16)(cid:16) (cid:68)(cid:13) (cid:68)(cid:13) (cid:68)(cid:13) chaPter 15 solution dynamics 573 (cid:19)(cid:20)(cid:16)(cid:16)(cid:16)(cid:16) (cid:68)(cid:68)(cid:13)(cid:11)(cid:68)(cid:11) (cid:68)(cid:13) (cid:68)(cid:68)(cid:11)(cid:11)(cid:68)(cid:13) (cid:68)(cid:11)(cid:68)(cid:13)(cid:68)(cid:11) (cid:68)(cid:11)(cid:68)(cid:13) (cid:18)(cid:16)(cid:16) (cid:68)(cid:11) (cid:68)(cid:11) (cid:68)(cid:13) (cid:17)(cid:16)(cid:16) (cid:68)(cid:13) 15.1 Why Solutions Form 574 15.2 Fats, Oils, Soaps, and Detergents 584 15.3 Saturated Solutions and Dynamic Equilibrium 588 15.4 Solutions of Gases in Liquids 594 chaPter 16 the Process of chemical reactions 609 16.1 Collision Theory: A Model for the Reaction Process 610 16.2 Rates of Chemical Reactions 616 16.3 Reversible Reactions and Chemical Equilibrium 621 16.4 Disruption of Equilibrium 634 chaPter 17 an introduction to organic chemistry, Biochemistry, and synthetic Polymers 657 17.1 Organic Compounds 658 17.2 Important Substances in Food 674 17.3 Digestion 688 17.4 Synthetic Polymers 690 chaPter 18 nuclear chemistry 715 18.1 The Nucleus and Radioactivity 716 18.2 Uses for Radioactive Substances 731 18.3 Nuclear Energy 737 (cid:11) (cid:38)(cid:79)(cid:70)(cid:83)(cid:72)(cid:90) aPPendix a measurement and units a-1 aPPendix B scientific notation a-4 answers to selected ProBlems a-6 Photo credits c1 glossary/index g-1 C 1 hapter a I C n ntroduCtIon to hemIstry 1.1 What Is Chemistry, I would watch the buds swell in spring, the mica glint in the granite, and What Can my own hands, and I would say to myself: “I will understand this, Chemistry Do for too. I will understand everything. You? Primo Levi (1919–87) Italian chemist and author, The Periodic Table 1.2 Suggestions for Studying Chemistry t is human nature to wonder—about the origins of the universe and of life, about 1.3 The Scientific their workings, and even about their meanings. We look for answers in physics, Method biology, and the other sciences, as well as in philosophy, poetry, and religion. Primo 1.4 Measurement and Levi could have searched for understanding in many ways, but his wondering led him Units to study chemistry…and so has yours, though you may not yet know why. 1.5 Reporting Values from Measurements 1.1 What is Chemistry, and What Can Chemistry Do for You? One thing is certain: Once you start studying chemistry, all kinds of new questions will begin to occur to you. Let’s consider a typical day. Your alarm rings early, and you are groggy from sleep but eager to begin working on a chemistry assignment that’s coming due. Chemistry has taught you that there are interesting answers to questions you might once have considered silly and childish. Preparing tea, for example, now makes you wonder why the boiling water bubbles and produces steam while the teakettle retains its original shape. How do the tea leaves change the color of the water while the teabag remains as full and plump as ever? Why does sugar make your tea sweet, and why is the tea itself bitter? You settle down with tea and newspaper, and the wondering continues. An article about methyl bromide, a widely used pesticide, says some scientists think it damages the ozone layer. What are methyl bromide and ozone? How does one destroy the other, and why should we care? How can we know if the ozone really is being depleted? Later, as you drive to the library to get some books you need to complete that chemistry assignment, An understanding of chemistry opens up you wonder why gasoline burns and propels your a window to the world around you.  4 Chapter 1 An Introduction to Chemistry car down the road. How does it pollute the air we breathe and what does the catalytic converter do to minimize the pollution? At the library, you wonder why some books that are hundreds of years old are still in good shape while other books that are only 50 years old have pages that are brown, brittle, and crumbling. Can the books with damaged pages be saved? Chemists can answer all these questions and others like them. They are scientists who study the structure of material substances—collectively called matter—and the changes that they undergo. Matter can be solid like sugar, liquid like water, or gaseous like the exhaust from your car’s tailpipe. Chemistry is often defined as the study of the structure and behavior of matter. Chemists do a lot more than just answer questions. Industrial chemists are producing new materials to be used to build lighter and stronger airplanes, more environmentally friendly disposable cups, and more efficient anti‑pollution devices for your car. Pharmaceutical chemists are developing new drugs to fight cancer, control allergies, and even grow hair on bald heads. In the past, the chemists’ creations have received mixed reviews. The chlorofluorocarbons (CFCs) used as propellants in aerosol cans are now known to threaten the Earth’s protective ozone layer. The durable plastics that chemists created have proved too durable, so when they are discarded, they remain in the environment for a long, long time. One of the messages you will find in this book is that despite the occasional mistakes and failures, most chemists have a strong social conscience. Not only are they actively developing new chemicals to make our lives easier, safer, and more productive, but they are also working to clean up our environment and minimize the release of chemicals that might be harmful to our surroundings (see Special Topic 1.1: Green Chemistry). As you read on in this book, you will find, perhaps to your disappointment, that only limited portions of each chapter provide direct answers to real‑life questions. An introductory chemistry text, such as this one, must focus instead on teaching basic principles and skills. Some of the things you need to learn in order to understand chemistry may seem less than fascinating, and it will not always be easy to see why they are useful. Try to remember that the fundamental concepts and skills will soon lead you to a deeper understanding of the physical world. Before you could run, you needed to learn how to walk. Before you could read a book or write a paper, you needed to learn the alphabet, build your vocabulary, and understand the basic rules of grammar. Chemistry has its own “alphabet” and vocabulary, as well as many standards and conventions, that allow chemists to communicate and to do efficient, safe, and meaningful work. Learning the symbols for the common chemical elements, the rules for describing measurements, or the conventions for describing chemical changes might not be as interesting as finding out how certain chemicals in our brains affect our moods, but they are necessary steps in learning chemistry. This chapter presents some suggestions for making your learning process easier and introduces you to some of the methods of scientific measurement and reporting. You will then be ready for Chapter 2, which gives you a first look at some of chemistry’s underlying concepts. 1.2 Suggestions for Studying Chemistry 5 S T Green Chemistry PECIAL OPIC 1.1 With knowledge comes the burden of into the water, various plants and animals begin to grow on responsibility. its bottom. This growth slows the ship’s progress and causes Paul T Anastas and Tracy C. Williamson, other problems as well, ultimately costing the shipping Green Chemistry industry an estimated $3 billion per year. Substances called antifoulants are painted on the bottom of ships to prevent the The chemical industry has made many positive contributions unwanted growth, but most of them can be harmful to the to modern life, but these improvements have come at a price. marine environment. Sea‑Nine is a more environmentally The chemical products themselves, the chemicals used to friendly chemical than the alternatives because it breaks down produce them, and the byproducts of their production have in the ocean more quickly and does not accumulate in marine sometimes been harmful to our health or the environment. organisms. Concern about these dangers has lead to a movement in the This is only one example of the progress that Green chemical industry that is sometimes called Green Chemistry Chemistry is making. Others will be presented in later or Environmentally Benign Chemistry. Its goal is to produce, chapters. process, and use chemicals in new ways that pose fewer risks to humans and their environment. Source: P. T. Anastas and T. C. Williams, Eds. Green Chemistry; In support of this goal, President Clinton inaugurated the (Washington DC: American Chemical Society,1996). Green Chemistry Program in March 1995, to be coordinated by the Environmental Protection Agency. As part of this program, the Green Chemistry Challenge Awards were set up, as part of the Green Chemistry Program, to “recognize and promote fundamental and innovative chemical methodologies that accomplish pollution prevention and that have broad application in industry.” Among the first award recipients was the Rohm and Haas Company, which received the Green Chemistry Challenge’s 1996 Designing Safer Chemicals Award for the development of 4,5‑dichloro‑2‑n‑octyl‑4‑isothiazolin‑3‑one, otherwise New, environmentally friendly marine antifoulants known as Sea‑Nine antifoulant. As soon as a new ship goes protect ships without polluting the water. 1.2 Suggestions for Studying Chemistry The will to succeed is important, but what’s more important is the will to prepare. Basketball Coach, Bobby Knight Let’s face it. Chemistry has a reputation for being a difficult subject. One reason is that it includes so many different topics. Individually, they are not too difficult to understand, but collectively, they are a lot to master. Another reason is that these topics must be learned in a cumulative fashion. Topic A leads to topic B, which is important for understanding topic C, and so on. If you have a bad week and do not study topic B very carefully, topic C will not make much sense to you. Because chemistry is time‑consuming and cumulative, you need to be very organized and diligent in studying it. There is no correct way to study chemistry. Your study technique will be decided by your current level of chemical knowledge, the time you have available, your strengths as a student, and your attitude toward the subject. The following is a list of suggestions  Chapter 1 An Introduction to Chemistry to help you take chemistry’s special challenges in stride. Use the Review Skills sections in this textbook. Starting with Chapter 2, each chapter begins with a section called Review Skills, complemented at the end of the chapter by a set of review questions that test those skills. The Review Skills section and the review questions identify the specific skills from earlier chapters that are necessary for success in the new chapter. If you have trouble with the tasks on the Review Skills list, you will have trouble with the chapter, so promise yourself that you will always review the topics listed in the Review Skills section before beginning a new chapter. Read each chapter in the textbook before it is covered in lecture. There are several good reasons why a relaxed pre‑lecture reading of each chapter is important. It provides you with a skeleton of knowledge that you can flesh out mentally during the lecture, at the same time guaranteeing that there will be fewer new ideas to absorb as you listen to your teacher talk. If you already know a few things, you will be better prepared to participate in class. Attend class meetings, take notes, and participate in class discussions. You will get much more out of a lecture, discussion section, or laboratory—and will enjoy it more—if you are actively involved. Don’t hesitate to ask questions or make comments when the lecture confuses you. If you have read the chapter before coming to class and paid attention to the lecture and you still have a question, you can be fairly certain that other students have that question too and will appreciate your asking for clarification. Reread the chapter, marking important sections and working the practice exercises. In the second reading, mark key segments of the chapter that you think you should reread before the exam. Do not try to do this in the first reading, because you will not know what parts are most important until you have an overview of the material the chapter contains. It is a good idea to stop after reading each section of text and ask yourself, “What have I just read?” This will keep you focused and help you to remember longer. You will find Examples in each chapter that show how to do many of the tasks that you will be asked to do on exams. The examples are followed by Exercises that you should work to test yourself on these tasks. The answers to these exercises are found at the end of the book. If you have trouble with a practice exercise, look more closely at the example that precedes it, but don’t get bogged down on any one topic. When a new concept or an exercise gives you trouble, apply the 15‑minute rule: If you have spent more than 15 minutes on an idea or problem and you still do not understand it, write down what you do not understand and ask your instructor or another student to explain it. Use the chapter objectives as a focus of study. At the end of each chapter is a list of Chapter Objectives that provides a specific description of what you should be able to do after studying the chapter. Notations in the text margins show you where to find the information needed to meet each objective. Your instructor may wish to add to the list or remove objectives from it. Many of the objectives begin with, “Explain…” or “Describe…”. You might be tested on these objectives in short essay form, so it is a good idea to actually write your responses down. This will force you to organize your thoughts and develop a concise explanation that will not take too much time to write on the exam. If you do it conscientiously, perhaps using color to highlight key phrases, you will be able to visualize your study sheet while taking the exam. 1.3 The Scientific Method  Many of the objectives refer to stepwise procedures. This book will suggest one procedure, and sometimes your instructor will suggest another. Write out the steps that you think will work best for you. The act of writing will help you remember longer, and you will find it much easier to picture a study sheet written out in your own handwriting than one printed in this book. Use the computer‑based tools that accompany the course. This textbook is accompanied by an Internet site that supplements the text. If you have access to it, you will find it useful at this stage in your studying. Work some of the problems at the end of the chapter. Do not try the end‑of‑chapter problems too soon. They are best used as a test of what you have and have not mastered in the chapter after all the previous steps have been completed. Note that many of I hear and I forget. I see and I remember. the problems are accompanied by the number of the learning objective to which they I do and I understand. correspond. (In fact, the problems serve as examples of ways in which you might be Chinese proverb tested on various chapter objectives.) Use the same 15‑minute rule for the problems as for the chapter concepts and exercises: If you have spent more than 15 minutes on any one problem, it is time to seek help. Ask for help when you need it. Don’t be shy. Sometimes five minutes in the instructor’s office can save you an hour or more of searching for answers by other means. You He who neglects to drink of the spring of experience might also consider starting a study group with fellow students. It can benefit those of is likely to die of thirst in you who are able to give help as well as those who need it. There is no better way to the desert of ignorance. Ling Po organize one’s thoughts than to try to communicate them to someone else. There may be other ways to get help. Ask your instructor what is available. Review for the exam. Read the list of objectives, asking yourself whether you can meet each one. Every time the answer is “No,” spend some time making it “Yes.” This might mean meeting with your instructor or study group, rereading this text, or reviewing your notes. Ask your instructor which objectives are being emphasized on the exam and how you are going to be tested on them. Your lecture notes can also provide clues to this. Lastly, work some more of the end‑of‑chapter problems. This will sharpen your skills and improve your speed on the exam. 1. The Scientific Method It’s as simple as seeing a bug that intrigues you. You want to know where it goes at night; what it eats. David Cronenberg, Canadian filmmaker Before beginning our quest for an understanding of chemistry, let’s look at how science in general is done. There is no one correct way to do science. Different scientific disciplines have developed different procedures, and different scientists approach their pursuit of knowledge in different ways. Nevertheless, most scientific work has certain characteristics in common. We can see them in the story of how scientists discovered the first treatment for Parkinson’s disease, a neurological condition that progressively