Chapter openers

A reaction A S bond breaking - bond forming (1365 kJ) + (- 1840 kJ) — -475 kJ The large negative A E for this reaction is one of the reasons why molecular hydrogen is a candidate to replace fossil fuels, as described in our chapter opener. 

The formation of mst on a steel surface, shown in our chapter opener illustrations, is an obvious manifestation of corrosion. Even more damaging effects of corrosion take place beneath the surface of the metal, where tiny cracks weaken the metal. 

In the chapter opener, you considered how the terms "natural" and "chemical" are used inaccurately. A natural substance is a substance that occurs in nature and is not artificial. A chemical is any substance that has been made using chemical processes in a laboratory. A chemical can also be defined as any substance that is composed of atoms. This definition covers most things on Earth. Go to the web site above, and click on Web Links to find out where to go next. Look up some nafura/poisons, pesticides, and antibiotics that are produced by animals, plants, and bacteria. Then look up some beneficial chemicals that have been synthesized by humans. Make a poster to illustrate your findings. 

A basic tenet of this book is to introduce and illustrate topics with concrete, interesting examples. In addition to their pedagogic value, Chapter Openers, Boxes, Demonstrations, and Color Plates are intended to help lighten the load of a very dense subject. I hope you will find these features interesting and informative. Chapter Openers show the relevance of analytical chemistry to the real world and to other disciplines of science. I can t come to your classroom to present Chemical Demonstrations, but I can tell you about some of my favorites and show you color photos of how they look. Color Plates are located near the center of the book. Boxes discuss interesting topics related to what you are studying or they amplify points in the text. 

The burning of fossil fuel is a chemical reaction, which, as you recall from Section 2.1, is a reaction that involves changes in the way atoms are bonded and results in the formation of new materials. For fossil fuels, these new materials are mostly carbon dioxide and water vapor. As we explore in future chapters, the only thing that determines the ability of atoms to form new materials in a chemical reaction is the atoms ability to share or exchange electrons—the atomic nuclei are not directly involved. The chemistry of an atom is therefore more a function of its electrons than of its nucleus. Nuclear fission, by contrast, involves nuclear reactions, which, as shown in the chapter-opening photograph, involve the atomic nucleus. In this sense, the study of the atomic nucleus is not a primary focus of chemistry. 

Fossil Fuels Are a Widely Used but Limited Energy Source warmed by the sun is because it is so big. Look at the lower right corner of the chapter-opening photograph, and you ll... 

Chapter Opener Joe Sohm/Chromosohm/The Stock Connection ... 

Chapter Opener Charles M. Falco/Photo Researchers, Inc. 6.3 Courtesy of the Bancroft Library, University of California, Berkeley 6.8 (left) Benjamin Cummings Publishers, Pearson Ed., (right)... 

Chapter Opener D.R. T. S. Schrichte/Photo Resource Hawaii ... 

Chapter Opener Digitalvision 9.4 (left, middle, center) Tom Pantages 9.13 CORBIS 9.15 Benjamin Cummings Publishers, Pearson Ed. 9.16 Photo Researchers, Inc. 9.17 (top) E. R. Degginger/Photo Researchers, Inc., (bottom) Jon Lemker/Earth Scenes 9.19 NASA 9.21 John Suchocki 9.22 John Suchocki ... 

Chapter Opener John Suchocki 12.5 Benjamin Cummings Publishers, Pearson Ed. 12.10 Liane Enkelis/Stock Boston 12.24 (top) Bob Gibbons/Photo Researchers, Inc., (b) Peter Arnold, Inc. 12.30 John Suchocki 12.31 Benjamin Cummings Publishers,... 

Chapter Opener John Suchocki 13.1 (left) John Suchocki, (right)... 

Chapter Opener Dr. J. Burgess/Photo Researchers, Inc. 14.3 Rurt Hostettmann 14.4 (top) David Nanuk/Photo Researchers, Inc., (bottom) Tom Pat Lesson/Photo Researchers, Inc. 14.5 (b) Upjohn ... 

Chapter Opener John Suchocki 15.2 Will Trayer/Visuals Unlimited 15.3 Norm Thomas/Photo Researchers, Inc. 15-5 (a, b) Nigel Cattlin/Photo Researchers, Inc., (c) Image Courtesy of Potash and Phosphate Institute 15.7 K. W Fink/Photo Researchers, Inc. ... 

Chapter Opener John Serrao/Visuals Unlimited 16.3 Bachmann/ Photo Researchers, Inc. 16.7 NEPCCO 16.8 SunRayTechonologies, Inc. 16.10 Saline Water Conversion Corporation, Saudi Arabia ... 

Why Do We Need to Know This Material Each chapter opens with a question students always have Why do we need to know this material Students should be encouraged to ask that question, and we present some answers in the chapter preview. There we describe how the concepts to follow fit into the framework of chemistry and relate to the everyday world. 

Chapter Opening Outline and Overview The chapter opening outline and overview were written to help students preview how the chapter is organized and what major concepts are to be covered in the chapter. 

This chapter opened with a drawing showing the naivete of the view that perception and consciousness are means of grasping physical reality, it ends with a drawing (Figure 4-6) that shows a truer and more complex view of perception (and, to some extent, of the consciousness behind it), in the center of the drawing are depicted... 

The first main part of this chapter opens with general aspects of chemical TA structures and the resulting physico-chemical properties, which determine the adequate choice of sample preparation, separation and detection techniques. Thereafter, pharmacological and toxicological basics of TA are outlined in general, followed by individual introduction of those TA, that are referred to in detail in this chapter. 

As you learned in the chapter opener, most elements do not exist in nature in their pure form, as elements. Gold, silver, and platinum are three metals that can be found in Earth s crust as elements. They are called precious metals because this occurrence is so rare. Most other metals, and most other elements, are found in nature only as compounds. 

As stated in the chapter opener, a solution is a homogeneous mixture. It is uniform throughout. If you analyze any two samples of a solution, you will find that they contain the same substances in the same relative amounts. The simplest solutions contain two substances. Most common solutions contain many substances. 

As stated in the chapter opener, an organic compound is a molecular compound of carbon. There are a few exceptions to this definition, however. For example, scientists classify oxides of carbon, such as carbon dioxide and carbon monoxide, as inorganic. However, the vast majority of carbon-containing compounds are organic. 

In this chapter, the occurrence, behavior, and roles of dithiolene complexes in biology are explored. This chapter opens with introductions of those biological systems that use metal dithiolenes for catalysis. Next the physical properties of the dithiolene-containing component of these systems are described. Following the behavior and characteristics of these bioinorganic dithiolene species,... 

Interiur lliuftratJon Academy Artworks and VovetaU PubiUhing Servim Chapter Opening llluatrationa ... 

To analyze a urine sample for THC (the chapter-opening molecule), the principal psychoactive component of marijuana, the organic compounds are extracted from urine, purified, concentrated, and injected into the GC-MS. THC appears as a GC peak with a characteristic retention time (for a given set of experimental parameters), and gives a molecular ion at 314, its molecular weight, as shown in Figure 13.6. 

ProbiGm 14.26 The NMR spectrum of melatonin, the chapter-opening molecule, is more complex than other examples we have encountered, but the chemical shift and splitting patterns observed for several peaks can be explained by what we have tecimed about NMR thus far. (a) Which protons in melatonin give rise to... 

Naturally occurring antioxidants such as vitamin E (the chapter-opening molecule) prevent radical reactions that can cause cell damage. 

Answer the following questions about ourcumin, the chapter-opening molecule. 

How does aspirin relieve pain and reduce inflammation Aspirin blocks the synthesis of prostaglandins, 20-carbon fatty acids with a five-membered ring that are responsible for pain, inflammation, and a wide variety of other biological functions. PGF2 , the chapter-opening molecule, contains the typical carbon skeleton of a prostaglandin. 

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