Times are changing more rapidly than ever—particularly in the vital areas of biochemistry, the environment, energy, drugs, and health and nutrition. In this revision, the authors of Chemistry for Changing Times strengthen the book's environmental focus by tying “Environmental Explorations” exercises to the media, and by implementing a framework that uses the ACS’s Environmental Principles, which are written by experts in the field. This reference puts chemistry in an approachable context and personalizes it for today's readers, enabling them to focus on evaluating information about real-life issues rather than memorizing rigorous theory and mathematics. Four chapters (19 through 22) are now posted online; Hill/Kolb is going green by reducing page length overall and moving four chapters from the text to the Web. A new, robust ebook with rich media assetsincludes Whiteboard problem-solving videos for every worked example in the book; section-ending self assessment questions from the book; and Green Explorations critical-thinking exercises link text and media.
Chemistry; Atoms; Atomic Structure; Chemical Bonds; Chemical Accounting; Gases, Liquids, Solids, and Intermolecular Forces; Acids and Bases; Oxidation and Reduction; Organic Chemistry; Polymers; Nuclear Chemistry; Chemistry of the Earth; Air; Water; Energy; Biochemistry; Food; Drugs; Fitness and Health; Chemistry on the Farm and in the Garden; Household Chemicals; Poisons.
A useful reference for anyone interested in learning more about chemistry in our everyday lives.
Chemistry for Changing Times is now in its tenth edition. Times have indeed changed since the first edition appeared in 1972, and they are now changing more rapidly than ever. The book is changing accordingly. Our knowledge base has expanded enormously since that first edition, never more so than in the last few years. We have faced tough choices in deciding what to include and what to leave out.
We live in what has been called the "information age." Unfortunately, information is not knowledge. It may or may not be valid. Our focus, more than ever, is on helping students evaluate information. We hope that some day we all will gain the gift of wisdom.
A major premise is that a chemistry course for students who are not majoring in science should be quite different from the course we offer our science majors. It must present basic chemical concepts with intellectual honesty, but it should not focus on esoteric theories or rigorous mathematics. It should include lots of modern everyday applications. The textbook should be appealing to look at, easy to understand, and interesting to read.
Three-fourths of the legislation considered by the U.S. Congress involves questions having to do with science or technology, yet only rarely does a scientist or engineer enter politics. Most of the people who make important decisions regarding our health and our environment are not trained in science, but it is critical that these decision makers be scientifically literate. A chemistry course for students who are not science majors should emphasize practical applications of chemistry to problems involving such things as environmental pollution, radioactivity, energy sources,and human health. The students who take our liberal arts chemistry courses include future teachers, lawyers, accountants, journalists, and judges. There are probably some future legislators, too.
Our main objectives in a chemistry course for students who are not majoring in science are as follows:
To attract a lot of students. If students are not enrolled in the course, we can't teach them.
To use topics of current interest to illustrate chemical principles. We want students to appreciate the importance of chemistry in the real world.
To relate chemical problems to the everyday lives of our students. Chemical problems seem more significant to students if they can see a personal connection.
To instill in students an appreciation for chemistry as an open-ended learning experience. We hope that our students will develop a curiosity about science, and will want to continue learning throughout their lives.
To acquaint students with scientific methods. We want students to be able to read about science and technology with some degree of critical judgment. This is especially important because many of the scientific problems discussed are complex and controversial.
To help students become literate in science. We want our students to develop a comfortable knowledge of science so that they find news articles relating to science interesting rather than intimidating.
New Features in the Tenth Edition
In preparing this new edition, we have responded to suggestions from users and reviewers of the ninth edition as well as using our own writing and teaching experience. The text is fully revised and updated to reflect the latest scientific developments in a fast-changing world.
Planning the Course
The organization of the text makes it easier for the instructor to skip sections or (in some cases) whole chapters. At most institutions, the course for nonscience majors brings together a tremendously heterogeneous group of students, with regard to both their science backgrounds and their academic interests. A major challenge to the instructor is to find the balance between these needs and interests. As authors we have tried to create a text that is flexible and that can be used in a variety of ways.
The first eight chapters deal with some of the basic chemistry, including atoms and elements, molecular structure, acids and bases, and oxidation-reduction reactions. Most of the numerical manipulations are concentrated in Chapter 6.
Chapter 9 and 10 introduce organic chemistry and polymers.
Chapter 11 through 14 (Earth, Air, Water, and Energy) center on environmental issues.
The final six chapters delve into biochemistry-related topics (Food, Household Chemicals, Fitness and Health, Drugs, Poisons) in some detail.
Clearly for a one-semester course, choices will have to be made. Though in the text there are references to later chapters where further details of a particular topic are to be found, the text does lend itself to using the parts each instructor finds the most important and useful to his or her students.
Changes in Content
Some of the more important changes, which were recommended by our users and reviewers, are as follows:
In Chapter 1 we changed Section 1.12, Energy: A Matter of Moving Matter, to deal mainly with temperature, and we moved most of the other material to Chapter 14 (Energy).
In Chapter 2 we revised the subsection "Explanations Using Atomic Theory."
In Chapter 3 we substantially rewrote the subsection "Building Atoms," eliminating the Bohr diagrams but retaining the idea of main-shell configurations.
In Chapter 4 we separated the section on nuclear equations (now Section 4.2) from discussion of background radiation. We alos added a new subsection, "Radioisotopes in Agriculture," with references to the potential banana crop disaster, to section 4.6, "Uses of Radiiostopes." We substantially rewrote Section 4.12, "Nuclear Power Pants."
In Chapter 7 we reorganized Section 7.2, "Acids, Bases, and Salts," to ;More carefully delineate the Arrhenius and Brensted-Lowry theories.
In Chapter 8, we changed the hydrogen-gain-or-loss definition of redox to more specifically relate to biochemistry (FAD and FADHZ).
In Chapter 11, we carefully updated data on municipal solid wastes and recycling, as well as data on world population and projections.
In Chapter 15, we shortened the discussion of protein synthesis and summarized the process with a new figure (Figure 15.27). We als9 updated the genetic engineering section.
In Chapter 17, we substantially rewrote the section on bleaches as well as the section on creams and lotions.
Additions to Pedagogy
The following changes have been made to strengthen and improve the pedagogy in this edition.
We have changed many of the worked-out Examples and their accompanying Exercises to improve pedagogy. To some Examples we have added voice balloons that guide the student through the problem-solving process. Others are carefully laid out in simple, easy-to-follow steps that are more effective in teaching the students particular skills. Many revised Examples and Exercises deal with issues that are more relevant to today's students.
In more cases, we have added a B Exercise to follow most of the Examples. The Example is followed by an A Exercise that is entirely parallel to the Example. Then a B Exercise follows that requires the student to incorporate information from earlier material. This should help the students synthesize their learning into a coherent whole rather than just learning isolated facts.
We have substantially revised the end-of-chapter exercises. There are now more matched pairs of Problems, with answers to odd-numbered problems given in Appendix C, as well as some more challenging Additional Problems to broaden the range of assignable problems.
We have changed many of the Critical Thinking Exercises to include more that deal with up-to-date, relevant issues.
We have added new Conceptual Examples to guide the students through the process of learning and understanding important chemical concepts.
We have added questions following the captions for some of the figures in each chapter to direct the student to the things that are particularly important to visualize and to expand on the concept illustrated in the figure.
For all chapters, we have added a new category, "Group Projects," to the end-of-chapter exercises. This will make it easy for instructors who want to encourage collaborative work and to make group assignments. In this way, the students' learning of chemistry can be extended far beyond the textbook. The web site contains keywords for beginning each of these projects.
We have increased the use of voice balloons in text displays as well as in problem solving to carefully guide the student through the learning process and thus improve the pedagogy.
Focusing on the importance of providing interesting, relevant applications, we have added several new box features: Spent Nuclear Fuel and Nuclear Proliferation (Chapter 4); Free Radicals (Chapter 5); The Kyoto Conference (Chapter 12); Arsenic Poisoning in Bangladesh (Chapter 13); Yucca Mountain (Chapter 14); Hydrogen Cars (Chapter 14); An Analogy for the Three Levels of Protein Structure (Chapter 15); Insect Resistance (Chapter 16); Anti-Aging Creams and Lotions (Chapter 17); Aromatherapy (Chapter 17); Fad Diets (Chapter 18); Combinatorial Chemistry (Chapter 19); NO-A Messenger Molecule (Chapter 19); Love: A Chemical Connection (Chapter 19); Solvent Sniffing: Self-Administered Anesthesia (Chapter 19); and Acrylamide (Chapter 20).
We have updated the References and Readings at the end of each chapter.
Eight new MediaLabs have been added in the tenth edition, for Chapters 2, 3, 6, 14, 16,17,19 and 20. The topics covered are as varied as they are current. The Companion Website also has search terms set up for all of the Group Projects in the chapters, to give the students a starting point in their research. All of the Web References listed in the text have been revised and updated both in the text and on the Companion Website. In addition, students will have access to Research Navigator, an online tool for searching the primary science literature, newspaper articles and chemistry organizations.
New color photographs and diagrams have been added. Visual material adds greatly to the general appeal of a textbook. Color diagrams can also be highly instructive, and colorful photographs relating to descriptive chemistry do much to enhance the learning process. We have added more illustrations that use both microscopic (molecular) and macroscopic (visual) views to help students visualize chemical phenomena.
Over the years, students have told us that they have found this textbook easy to read. The language is simple, and the style is conversational. Explanations are clear and easy to understand. The friendly tone of the book has been maintained in this edition. Since the format and the amount of open space on a page also contribute to readability, we have made conscious improvements in the design of this edition. For example, many of the margin notes have been incorporated directly into the text to ensure that pages don't appear to be crowded.
Units of Measurement
The United States continues to use the traditional English system for many kinds of measurements even though the metric system has long been used internationally. A modern version of the metric system, the Systeme International (SI), is now widely used, especially by scientists. So what units should be used in a text for liberal arts students? In presenting chemical principles, we use primarily metric units. In other parts of the book we use those units that the students are most likely to encounter elsewhere in the same context.
The structures of many complicated molecules are presented in the text, especially in the later chapters. These structures are presented mainly to emphasize that they are actually known and to illustrate the fact that substances with similar properties often have similar structures. Students should not feel that they must learn all these structures, but they should take the time to look at them. We hope that they will come to recognize familiar features in these molecules.
The Glossary (Appendix B) gives definitions of terms that appear in boldface throughout the text. These terms include all key terms listed at the end of each chapter.
Questions and Problems
The end-of-chapter exercises include review questions, a set of matched-pair problems, and suggested projects. Answers to many review questions and to all the odd-numbered problems are given in Appendix C. As mentioned earlier, all chapters contain worked Examples and many paired Exercises. Answers to all the in-chapter exercises are also given in Appendix C.
References and Suggested Readings
An updated list of recommended books and articles appears at the end of each chapter. A student whose interest has been sparked by a topic can delve more deeply into the subject in the library. Instructors might also find these lists useful.
To the Student
Welcome to Our Chemical World!
Chemistry is fun. Through this book, we would like to share with you some of the excitement of chemistry and some of the joy of learning about it. We hope to convince you that chemistry does not need to be excluded from your learning experiences. Learning chemistry will enrich your life--now and long after this course is over--through a better understanding of the natural world, the technological questions now confronting us, and the choices we must face as citizens within a scientific and technological society.
Chemistry Directly Affects Our Lives
How does the human body work? How does aspirin cure headaches, reduce fevers, and perhaps lessen the chance of a heart attack or stroke? Is ozone a good thing or a threat to our health? Are iron supplement pills poisonous? Is global warming real? If so, did humans contribute to it, and what are some of the possible consequences? Why do most weight-loss diets seem to work in the short run but fail in the long run? Why do our moods swing from happy to sad? Can a chemical test on urine predict possible suicide attempts? How does penicillin kill bacteria without harming our healthy body cells? Chemists have found answers to questions such as these and continue to seek the knowledge that will unlock still other secrets of our universe. As these mysteries are resolved, the direction of our lives often changes--sometimes dramatically. We live in a chemical world--a world of drugs, biocides, food additives, fertilizers, fuels, detergents, cosmetics, and plastics. We live in a world with toxic wastes, polluted air and water, and dwindling petroleum reserves. Knowledge of chemistry will help you to better understand the benefits and hazards of this world and will enable you to make intelligent decisions in the future.
We are all chemically dependent. Even in the womb we depend on a constant supply of oxygen, water, glucose, and a multitude of other chemicals.
Our bodies are intricate chemical factories. They are durable but delicate systems. Innumerable chemical reactions that allow our bodies to function properly are constantly taking place within us. Thinking, learning, exercising, feeling happy or sad, putting on too much weight or not gaining enough, and virtually all life processes are made possible by these chemical reactions. Everything that we ingest is part of a complex process that determines whether our bodies work effectively or not. The consumption of some substances can initiate chemical reactions that will stop body functions altogether. Other substances, if consumed, can cause permanent handicaps, and still others can make living less comfortable. A proper balance of the right foods provides the chemicals and generates the reactions we need in order to function at our best. The knowledge of chemistry that you will soon be gaining will help you better understand how your body works so that you will be able to take proper care of it.
We live in a world of increasingly rapid change. It has been said that the only constant is change itself. At present, we are facing some of the greatest problems that humans have ever encountered, and the dilemmas with which we are now confronted seem to have no perfect solutions. We are sometimes forced to make a best choice among only bad alternatives, and our decisions often provide only temporary solutions to our problems. Nevertheless, if we are to choose properly, we must understand what our choices are. Mistakes can be costly, and they cannot always be rectified. It is easy to pollute, but cleaning up pollution once it is there is enormously expensive and often very difficult. We can best avoid mistakes by collecting as much information as possible and evaluating it carefully before making critical decisions. Science is a means of gathering and evaluating information, and chemistry is central to all the sciences.
Chemistry and the Human Condition
Above all else, our hope is that you will learn that the study of chemistry need not be dull and difficult. Rather, it can enrich your life in so many ways-through a better understanding of your body, your mind, your environment, and the world in which you live. After all, the search to understand the universe is an essential part of what it means to be human.