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edited by BAIRDW. LLOYD
Center for Chemical Education Miami University Middletown. OH 45042
A General Chemistry Course that Focuses on the Emerging Chemical Sciences P. M. Owens United States Military Academy West Point, NY 10996
The objective of the revised General Chemistry course f i r s t implemented i n t h e fall of 1993 a t t h e United S t a t e s Military Academy i s t o s p e n d a significant amount of time examining the important modern disciplines i n which chemistry plays a key role. Because many of the scientific advances today a r e interdisciplinary i n nature, a course with this focus introduces students to a number of sciences and gives them a better appreciation for the interconnectivity of principles that govern t h e physical world. What Are the Relevant Areas of Chemistry? Chemistry lies a t the heart of three emerging sciences that are driving technical change in the world today: Materials science Biochemistry and molecular biology Environmental science
A 1 9 8 8 A m e r i c a n C h e m i c a l Society publication, Biotechnology a n d Materials Science: Chemistry for the Future (11, outlined the central role t h a t chemistry h a s i n two of these increasingly important fields. The importance of chemistry to the third field, environmental science, was evident a t the 1994 Spring American Chemical Society national meeting, where t h e Division of Chemical Education sponsored a five-part symposium o n "Environmental Chemistry Education" (2).T h e Chemistry degree certified by the American Chemical Society's Committee on Professional Training now includes degree options i n all three of these areas: Biochemistry (a program developed i n conjunction with the American Society of Biochemistry and Molecular Biology), Materials (added in the 1988 addendum), and Environmental (added i n January 1994). Course Texts Unfortunately, the "ideal" General Chemistry text for a course that focuses on materials science, life science, and environmental science has not yet been written. A brief survey of nine widely used texts (eight published i n 1993 or 1994) shows that they devote an average of 1 113 chapters to these three areas combined (remarkably, people still write general chemistry texts that do not devote a single chapter to any of these fields). Only one of the texts-AtPresented at the 13th Biennial Conference on Chemical Education. Bucknell University, August 1994. 528
Journal of Chemical Education
oms, Molecules, and Reactions: An Introduction to Chemistry (Gillespie e t al.) (3bincludes three separate chapters on these topics. Two supplemental texts a r e heing used to teach the applications-based portion of the revised general chemistry course a t West Point. The first, Modern Applications of Chemistry (41, focuses on four areas: materials science, the chemistry of life, environmental chemistry, a n d militarv chemistrv. Manv of the c h a ~ t e r si n this hook were extracted from various texts while others were written by faculty members here. The second supplemental text, Peter Thrower's Materials in Todav's World ( 5 ) .provides a n excellent d e s c r i ~ t i v eoverview of materiais, properties and includesAnumerous illustrative case studies. Because Thrower's text contains no problem sets, exercises for his chapters were written a n d incorporated i n t h e Modern Applications text. Several chapters on materials also were added to complement Thrower's approach. Materials, Life Science, and Environmental Topics Taught Tables 1-3 outline the specific topics examined during the materials science, life science, and environmental science blocks of the revised general chemistry course. The lists have been compiled in sufficient detail to provide a framework for those who mav wish to structure a suhcourse in any or . i l l ol'thrir areas 'I'hr two supplemental texts dtr.xrih(d e:irli(>rnrovidc. student r ~ d i n a on s ruch of these topics. ater rials science precedes life-science hecause the introduction of ~ o l n n e formation r via condensation reaction serves a s natural prelude to the major classes of hiopolymers: polysaccharides, proteins, and nucleic acids. Environmental science is examined last since key environmental topics such a s toxicology and hiodegradation involve concepts developed earlier in life science. After a n introduction to materials and their properties, materials science is taught by studying each of the major materials categories: ceramics, metals, and polymers. The special materials classes of composites, semiconductors, a n d superconductors also a r e examined. Several specific material properties are taught in conjunction with appropriate material classes; e.g., mechanical properties with metals, t h e r m a l properties with ceramics, and electrical properties with semiconductors. To pique student interest, case studies highlight how material properties can he improved to meet particular applications. Of the three emerging disciplines, the life sciences are the most highly developed and there are a number of suitable references that can be used to teach this subject. After a n overview of cell structure and function, a systematic study of the major biochemical classes: carbohydrates, lipids, proteins, enzymes, and nucleic acids provides a convenient mechanism to focus on this field. The Modern Ap-
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Table 1. Materials Science Topics Examined in General Chemistry A. Overview of Materials Science 1. Types of materials: Metals, ceramics, and polymers 2. Levels of structure: Electronic, atomic, crystal, micro (grain), macro 3. Bonding B. Properties of Materials 1. Properties: mechanical, electrical, thermal, optical, environmental 2. Stress-strain curves: modulus, elasticplastic deformation, ductility 3. Thermal expansion of materials 4. Crystal structure and slip planes 5. Defects in materials: extrinsic-intrinsic point defects, dislocations C. Metals and Alloys 1. Metals production 2. Strengthening: Work and precipitation hardening, grain refining 3. Fe-C phase diagrams: two-phase regions, lever rule, e~ltectim . ... .. 4 Case S t ~ o yA -LI alloys for aerospace 5 Case S t ~ o yrlSLA stees lor car ooanes
D. Polymers 1 AOOIon an0 conoensat on po ymer zat on 2 Cross nr, ng an0 stllfen ng 3 Case st.ot From r-ober to ABS E. Ceramics 1. Production from powders via sintering 2. Suoerconductors 3. ~ i k i ceramics n ~ less brittle: Compression, grain size. flame polishing 4. Heat conduction: Phonons, electrons, atom-atom collisions 5. Case study: Glass ceramics for cookware F Semiconductors 1. Band energy diagrams: conductors, semiconductors, insulators 2, Impurities and p-typeln-typesemiconductors 3, Interaction of EMR with conductors, semiconductors, and insulators 4. P-n junction rectifier 5. Case Study: Silicon solar cells G. Composites 1. Carbon fiber production 2. Carbon reinforced plastic and carbon-carbon composites 3. Composites and stress-strain curves 4. Composite materials: fiberglass, wood, tires H. Future materials 1. Ceramic engines 2. Powder metallurgy 3. Conducting polymers
plications t e x t contains separate chapters o n each o f these biochemical classes. Less information i s available t o exami n e the advances in molecular biology, y e t these topics are extremelv imnortant. Readines " o n recombinant D N A t e c h nology a n d applications are incorporated in t h e Modern Applications t e x t w i t h i n t h e chapter o n nucleic acids. Of t h e three e m e r d n p sciences, environmental science i s clearly t h e area that h a s n o t sufficiently m a t u r e d t o discern easily w h a t basic topics are needed t o cover t h i s m u l tidisciplinary, r a p i d l y evolving field. Environmental chemi s t r y i s t a u g h t b y focusing o n t h r e e m a j o r regions: t h e atmosphere (atmospheric environmental chemistry), t h e aquasphere (aquatic environmental c h e m i s t q ) , a n d t h e biosphere (toxicology).
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What Fundamental Topics Are Studied First? Materials science, l i f e science, a n d environmental science r e l y o n k e y chemical concepts. Before students study these sciences, they should l e a r n t h e fundamental principles t h a t are i m p o r t a n t t o these fields. Table 4 outlines t h e
Table 2. Life Science Topics Examined in General Chemistrv A. Overview of Cell Structure 1. Biochemical classes and cell composition 2. Anaboliccatabolic and coupled reactions 3. Prokaryotes and eukaryotes 4. Membranes and organelles 8. Carbohydrates 1. Monosaccharidesand cycliclstraight-chain structures 2. Oligosaccharides and polysaccharides 3. Glucose metabolism and blood glucose levels C. Lipids 1. Terpenes 2. Steroids: anabolic steroids, hormones 3. Waxes 4. Fatty acids: saturated versus unsaturated 5. Triglycerides: energy storage 6. Phosphoglycerides: membrane structure and transport D. Protetns 1. Amino acids and acid-base properties 2. Protein bonding: peptide, disulfide, H-bond, ionic, hydrophobic 3. Protein structure: priman! secondary (a and B), . . tertiary, quaternary 4. Denaturing of proteins: heat, pH, redox, H-bond solvents, metal salts E. Enzymes 1. Classes 2. Models of action: induced-fit and lock-and-key 3. Active sites and coenzymes 4. Enzyme kinetics: turnover number, E-S stability, temperature, pH F. Nucleic Acids 1. Nucleotides and polynucieotides 2. Central Dogma G. Molecular Biology: .. Recombinant DNA techniques and applications 1. Recombinant DNA generation 2. DNA libraries 3. Engineering bacterial genes 4. Engineering plant genes
Table 3. Environmental Science Topics Examined in General Chemistrv A. Atmospheric Environmental Chemistry 1. Atmospheric regions and composition 2. Photodissociation and photoionization processes 3. Stratospheric ozone and ozone depletion 4. Tropospheric chemistry: acid rain, photochemical smog, CO and resoiration. COdH9O and climate B Aq-at8c ~nwronmenta~ h e slry h 1 Oceans and oesal nat on processes 2 Water q.al ly 0 2 ofooegraoaoe leve s. aerobc anaerooc bacteria 3. Municipal water treatment 4. Sewage treatment: primary, secondary, tertiary 5. Fate and transport of contaminants: transport and transformation C. Toxicology 1. Dose-response curves 2. Routes of exposure 3. Body organ response to chemicals 4. Tvoes of toxic effects ,, 5. Exposure llmits 6. Risk assessment
topics covered in general chemistry d u r i n g t h e fundamentals overview (first two-thirds) o f general chemistry. Subjects such as chemical bonding, i n t e r m o l e c u l a r forces, thermodynamics, kinetics, a n d equilibria are extremely i m p o r t a n t in materials, environmental, a n d l i f e sciences.
Volume 72
Number 6
June 1995
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Table 4. Important General Chemistry Topics for Studying the Chemical Sciences Atomic Structure . .. Energy Levels and EleclromagnetfcRao at on Cnemcal Bond ng an0 Mo ecdlar Geomelry React" l y ano Per8ootc ty Gases Liquids and Solids Solutions and Intermolecular Forces Equilibria Acids and Bases Oxidation-Reduction Solubility and Complexation Thermodynamics Kinetics Organic Chemistry Organic chemistry stands out a s another key area that should precede the study of all three fields. Where Do We Go from Here? Students feedback from the course indicates a strong desire to extend the coverage of the chemical sciences to the entire second semester of general chemistry. I t is anticipated that a n expansion to a n entire semester of applications will be made once suffkient text material is developed for the application blocks and once a textbook that succinctlv covers fundamental chemical principles is adopted f i r the course. There also is a strong student sentiment to combine the two supplemental texts. This will be corrected with the next edition of the text. Acknowledgment I would like to thank Frank Guthrie for numerous helpful discuss~onsand fur insightful comments on this manuscnot. I also would like to thank Hnird Lloyd for thoughrful suggestions on topics to emphasize. Literature Cited 1. Good. M. L.. Ed. Biaiechchnolom and Moteriala Science: Chemlatry for the Futuw
1994.
4. Owens, P M.: Costella, R. G.; Hams. W. F:Harrison, S. G.; Eshelman. J. R. Eds. Modem Applicohons ofchemirtiy; KendalliHunt Publishing Company: hrbuque, 1.4.1994. 5. ~h~~~~~peterA. Molenola in lbdayb World; McGraw-Hill, h e . :New York, 1992.
A Novel Spiral Approach to Introductory Chemistry Using Case Studies of Chemistry in the Real World Christina Poth Brink, David E. Goodney, Norman J. Hudak. and Todd P. Silverstein willameke university,' Salem, OR 97301 In a n effort to respond to the many concerns regarding the general chemistry sequence, several members of our chemistry department spent the last four years reviewing our current curriculum. ~ l a n n i n emaior revisions in our introductory course, and hevelopLg t6e written materials for a new curriculum. The revisions were implemented for the first time during the 1993-1994 academic year. We have attempted to address the problems of the general chemistry c;rriculum by developing a two-course sequence that uses the first semester to introduce qualitative discus'WIIamene Jn verslry is a pr vate, omera arts nst tJtlon ma! enrolls abo~t1600 ~ndcrgrao~ale slLdents Tne cnemlslry oepanment is ACS accreo lea and nas emp oyeo a traalt.ona 4-year car CL Jm lor chemistry majors until this past academic year.
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Journal of Chemical Education
sions of most chemical concepts, from structure and bonding to kinetics and chemical equilibrium. S t u d e ~ t swho drop after this course get a well-rounded introduction to the methods and concerns of chemistry Furthermore, exceptionally well-prepared high school students should more easilv . d.a c e out of this course and start with the second-semester course. The second-semester course then s ~ i r a l back s through the same chemical concepts in a more rigorous and quantitative way. The second sniral ex~loresfundamental chemical ideas in a framework of real-world case studies such as lasers, air oollution. and blood chemistri. Each case studv builds on Lhemical knowledge from the &-st semester, but then it explores the concepts in greater depth and with greater mathematical sophistication. This approach allows students to appreciate the concept's application in a rigorous and non-superficial manner. When we listed the tonics we wanted to survev in the first semester, it was apparent that no suitable textbook existed. We briefly considered preparing a detailed list of sections and even paragraphs from a standard text for students to read. in effect. a road map through the text. We quickly rejected that idea a s u n s a t i s f a c t o ~and confusing for students. Our best alternative was to cut and paste a n existing textbook. With the publisher's and authors' permission, we chose to modify Kotz and Purcell's Chemistry and Chemical Reactivity, second edition. We took apart the Kotz and Purcell text, then reassembled it, along with some of our own original text, into a manuscript for the students. This manuscript refers students back to color nhotos. some tables. and fieures in the orieinal text rather ihan reproducing them. &dents buy hotcthe manuscript and the orieinal text. While all of the reading assienments come from ;he manuscript, students are directed to use the text's fieures and tables as needed. This method has the advantage of preserving the copyright privileges of the authors and oublisher while providing a manuscript tailored to the needs of this parti'cular co&e. For the Second semester, students simply purchase a separate Case Study manuscript. We have dubbed this new year-long curriculum the s p i r a k a s e study approach.
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First Semester: Qualitative Survey The topics covered in the first semester of the spiral approach to Introductory Chemistry are listed below. 1. The Tools of Chemistry
Scientific Method Units and Measurement Significant Figures Energy
2. The Stuff of Chemistry Density, Classification of Matter Atomic Theory and Structure Introduction to the Periodic Table Ions, Ionic compounds Compound Naming The Mole Molecular formulas, Molar mass 3. Chemical Reactions Balancing equations Stoiehiometry Solubility Acids and Bases Redox Reactions Net Ionic equations Common Chemical Reactions Common Organic Functional Groups
