Chemistry for Nonscientists
W h a t can one say generally about the content and style of an introductory, terminal course in chemistry for nonscientists?-especially a course for those college students who, while they probably know the meaning of "50 percent," may not be certain of the precise meaning of "15 percent"; who may workout the quotient 88/100 by long division (if, indeed, that is viewed as possible, 100 being larger than 88); and who, if asked, indicate that their dominant feeling toward the course (not yet begun) is one of fear and apprehension. For such students, probably there is nothing that must be covered in the course. Well, almost nothing. In an introductory course on chemistry, most teachers would probably discuss the meaning of chemical change, the idea of elementary composition, and the atomicmolecular hypothesis. Beyond that it is not easy, or perhaps desirable, to specify course-content. Chemistry is a broad discipline. No four, or eight, year curriculum, even less a single course, can cover it all. To avoid future shock in chemical education, we need diversity. A 1961 poll of college chemistry teachers on what should be in an introductory chemistry course ranked biochemistry in a list of 230 items 219th, entropy 229th ( 1 ) . Still, if a course is to be successful, by anyone's measure, in addition to appropriateness in level and content, and common sense and good will on the instructor's part, there must be present enthusiasm. But the substrate from which springs enthusiasm may differ tremendously from instructor to instructor. A chemical physicist will not wax enthusiastic over the same things as does an inorganic, or analytical, chemist. Conceivably a course in chemical physics could be made highly rewarding, stimulating, interesting, and popular with nonscience majors, even those uncertain of the meaning of "15 percent." Like many chemistry teachers, however, we have found that lecture experiments are an excellent way to generate interest in chemical phenomena. Lecture experiments may generate more interest in chemistry among nonscience majors than does conventional laboratory work. Unless in excellent practice, most people derive more pleasure from hearing (or watching) good music (or tennis), e.g., than from trying to play it. Surprisingly, many of our best-received experiments have been unrehearsed. This experience is consistent with the suggestion that the chief function of a teacher is to act out for his stuPresented at the Chicago Group Meeting of the College Chemistry Consultants Senrice, September 11,1970.
provocative opinion dents what it means to be a professional (2). How can a chemist perform that act for a large group? Perhaps best by trying to answer questions raised by the class and by nature. Many experiments, unrehearsed, do not proceed precisely as one anticipates-and has perhaps suggestedthey might. One has then to decide, in front of the class, what to try next, in an effort to obtain, everitually, interpretable results. An illustration may be given. First it is helpful, however, to realize that there are no crucial experiments in science (8). No experiment establishes conclusively any point of chemical theory. No point of chemical theory can be established conclusively by any experiment. This feature of science has another aspect, more charming to experimentalists, perhaps, than to theoreticians. From a reduetionist's point of view, there are no simple chemical phenomena. Almost any experiment in chemistry illustrates almost any part of chemical theory. Almost any part of chemical theory can be illustrated by almost any experiment (4). In a course one can bring in almost any experiment anywhere and make something of it. Sometimes we do Priestley's test for the "goodness of air" [mixing the "air" to be tested with an excess of NO, over water (6)] to illustrate, e.g., one man's methods in science; or to describe the discovery and properties of oxygen; or the chemical characteristics of NO, NO*, and the dimers of NO*; or Gay-Lussac's law of combining volumes; or (regarding the reaction of NO2 with water), gas solubility, oxidation-reduction, chemical kinetics, reaction mechanisms, and the terms nucleophilic and electrophilic; or valence theory and Linnett's extension of classical structural theory; or the chemistry of combustion, rusting, or brown cit,ies. Similarly, a course of lectures can be based on ammonium dichromate (6), or a candle (7). Once we planned to use Priestley's test to determine how much oxygen was in a flask after a member of the class had exhaled into it. Just as we collected the sample of bad air, over water, on a Friday, the bell rang. On Monday we found 18.5% oxygen, much higher than anticipated. Not until outside the classroom did I think of what I should have thought of in class (a common postrexam experience). The following day, acting on the supposition that oxygen had diffused from the room into the flask and nitrogen, on the balance, in the opposite direction, we put pure nitrogen into a flask and allowed it to stand over water (under the atmosphere). A day later it tested out 8% oxygen. This experiment led to further experiments, on fish (introduced by some student into the glass tank used for a Volume 48, Number 4, April 1971
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pneumatic trough)-bubbling through oxygen and nitrogen, a t difyerent temperatures-and, thence, to some observations on thermal pollution. All very simple, yes, yet interesting and informative, to the class and the instructor. Frequently, i t is not what but why one does something that is important. The content of an experiment is as important as the ezperiment itself. Most compilations of experiments are only half the story. They are useful but, by themselves, like the notes on a piano, hardly music to the soul. Another point. Generally chemical experiments are more interesting to watch than physical experiments. Almost everyone has seen mechanical contrivancesgears, cogs, pulleys, waves, colliding billiard balls, objects sliding or rolling down inclined planes, perhaps even a mercury barometer. But the nylon rope experiment, or copper dissolving in nitric acid-that is remarkable, almost unbelievable. In our experience with nonscientists, the phenomena of organic and inorganic chemistry reveal the essence of chemistry more vividly than do the phenomena of physical chemistry. For a lecture-experiment-based course in chemistry, almost any "old-fashioned, lowlevel" text that discusses chemical reactions is useful. My first choice would be Meudeleeff's two volumes on chemical principles-unfortunately now out of print. Finally, we suggest that, if one must examine (and grade) the students, try to make the examinations as easy as possible. Tell them what is going to be on the examinations.
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Many of these things are not easy to do. During a course one may have a feeling of sacrifice and restraintof not doing many things one has labored long and hard to learn to do. Later, after one has had an opportunity to discuss the course with the students, this feeling of sacrifice and restraint will probably vanish. In summary, in a chemistry course for nonscientistsone whose chief (if not sole) goal is to generate an interest in, even a liking for, science-in such a course style is more important than course content. Today we hear much about relevance-almost always with regard to course content. Relevance, however, is probably more a function of style than content. Nothing learned poorly is long relevant. Nothing learned well is predictably irrelevant, in the long run. Henry A. Bent North Carolina State University Raleigh, North Carolina 27607 Literature Cited (1) N m c ~ ~ w r rR.. * . J. Cn=la. Eona..38,255 (1981). (2) A point emphaaiaed by L. K. Nu=; see BENT.A. A,. ' W h y Lecture?" Pure and AppliedCham.. 22,23(1870). (3) Donela, P.. "Aim and structure of Physioal Th90desU (Tmn*lalo,: WIBNER,P. P.), Princeton, N. J.. 1954. (4) A point emphaaised by L. E. Strong,private oommunioation. (5) CONANT.J. B., "Harvard Case Histories in Experimental Science," Haward University Presa, Cambridge, Mass., 1957,Vol. I, Chap. 2. (6) Cf. F I N ~ O LJ.TE., . J. CBEM.EDUC..47.533 (1970). (7) Fmmar. M.."The Chemical Hiaton. of the Candle." Collier Booka.
