Chemistry [antikvár]

To the ProfessorBecause of the positive response to the fourth edition of this text, the fifth edition of Chemistry continues in the same spirit: a presentation of the concepts of chemistry in a clear, interesting, and student-friendly manner. However, we have gone over every page in the fourth edition thoroughly, fine-tuning in some cases and substantially rewriting in others. In doing so, we have incorporated numerous constructive suggestions from instructors who used the previous edition.Since visual material is especially important for learning general chemistry, which typically presents a pictorial view of chemical concepts, the illustrations representing the microscopic world of chemistry have been redone in this edition to improve their clarity and appearance. Special illustrations and color photographs integrate descriptive chemistry with chemical principles, and many new Chemical Impact features emphasize practical applications of newly learned concepts.Important Features of the Fifth Edition The new edition of Chemistry contains numerous discussions, illustrations, and exercises aimed at overcoming common misconceptions. It has become increasingly clear from our own teaching experience that students often struggle with chemistry because they misunderstand many of the fundamental concepts. In this text, we have gone to great lengths to provide illustrations and explanations aimed at giving students more accurate pictures of the fiindamental ideas of chemistry. In particular, we have attempted to represent the microscopic world of chemistry so that students have a picture in their minds of "what the atoms and molecules are doing." Also, we have placed a larger emphasis on the qualitative understanding of concepts before quantitative problems are considered. Because using an algorithm to correctly solve a problem often masks misunderstandingstudents assume they understand the material because they got the right "answer"it is important to probe their understanding in other ways. In this vein we have included a number of conceptual questions at the end of each chapter that are intended for group discussion. It is our experience that students often learn the most when they teach each other. Students are forced to recognize their own lack of conceptual understanding when they try and fail to explain a concept to a colleague.With a strong problem-solving orientation, this text talks to the student about how to approach and solve chemical problems. We have made a strong pitch to students for using a thoughtful and logical approach rather than simply memorizing procedures. In particular, an innovative method is given for dealing with acid-base equilibria, the material the typical student finds most difficult and frustrating. The key to this approach involves first deciding what species are present in solution, then thinking about the chemical properties of these species. This method provides a general framework for approaching all types of solution equilibria.I The text contains almost 300 sample exercises, with many more examples given in the discussions leading to sample exercises or used to illustrate general strategies. When a specific strategy is presented, it is summarized, and the sample exercise that follows it reinforces the step-by-step attack on the problem. In general, in approaching problem solving we emphasize understanding rather than an algorithm-based approach.I We have presented a thorough treatment of reactions that occur in solution, including acid-base reactions. This material appears in Chapter 4, directly after the chapter on chemical stoichiometry, to emphasize the connection between solution reactions and chemical reactions in general. The early presentation of this material provides an opportunity to cover some interesting descriptive chemistry and also supports the lab, which typically involves a great deal of aqueous chemistry. Chapter 4 also includes oxidation-reduction reactions, because a large number of interesting and important chemical reactions involve redox processes. However, coverage of oxidation-reduction is optional at this point and depends on the needs of a specific course.I Descriptive chemistry and chemical principles are thoroughly integrated in this text. Chemical models may appear sterile and confusing without the observations that stimulated their invention. On the other hand, facts without organizing principles may seem overwhelming. A combination of observations and models can make chemistry both interesting and understandable. In addition, in those chapters that deal with the chemistry of the elements systematically, we have made a continuous effort to show how properties and models correlate. Descriptive chemistry is presented in a variety of ways--XII