edited by: DAVID A. PHILLIPS Wabash College Crawfordsville. IN 47933 PRUDENCE PHILLIPS Crawfordsville High Schwl Crawfordsviile. IN 47933
Some Reasons for Teaching Descriptive Chemistry When I was invited to prepare this short article on my reasons for teaching descriptive chemistry, many thoughts went through my head. I remembered as a high school student in the 'fifties studying a course that was essentially all descriptive chemistry, with very little mathematics and only a limited amount of theory. I next recalled the early 'sixties when I started to teach CHEMStudy chemistry and theory took over as the dominant force. Now in the 'eighties I still teach a very theoretical course, hut theory and description are more com~atihle.There are some fundamental, philosophical reasons f& my planned strategy. Some Real Chemistry
Theoretical chemistry without some descriptive chemistry is not real chemistry. I feel compelled to make this clear to all my chemistry students, whether they are in a beginning, eeneral course or are oart of mv advanced olacement course. kature makes use of descripti;e chemistr; and so does man, whether students realize it or not. I perceive my role as making theory as real as I can by connecting it to "chemistry in the real world." This is not alwavs an easv task to accom~lish.but I keep trying nevertheless. Some Relevant Chemistry
Descriotive chemistrv couded with DroDer theow makes for relevant chemistry. 'iho m.uch of either of these types with little nmsidemtiun of the other leads students to we a distorted picture of this discipline that we call chemistry. Heavy emphasis on principles and theories leaves students without an appreciation of the chemistry that is all around them. There are times that a qualitative discussion may accomplish more for my students than the best of mathematical treatment. In short, I make a concerted effort to put both of these facets in their proper perspective daily and do my best to plan my lecture-discussions with that in mind. Some Balanced Chemistry
We need balance as well as a synthesis of facts and theories in all introductory courses. Descriptive facts can enhance theory and theory can help descriptive truths. I consider it my responsibility to handle this relationship both deftly and with careful nlannine. I would never consider making my students learn stephy-step processes as I had to do in the 'fifties, but I do want them to know how chemistry has made their everyday living better.. in soite . of the n w r Dress that chemistw often receives. I expect my students to gei a full appreciation for the manner
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Teaching of Chemical Reactions and Syntheses The dictionaw defines chemistrv as "the science that treats the structure, composition, and properties of substances and of their transformations." This is an apt definition. It follows then that a chemist is one who is knowledgeable about the properties and transformations of substances. This is why I firmly believe we are ohliged to teach our chemistry students some fundamental reactions and syntheses which we think all chemists should know. Unfortunately, during the last couple of decades reaction and synthesis chemistry has been referred to as descriptive chemi8try. In fact, it has conveyed a had connotation among many teachers. These teachers are more comfortahle teaching th;. principles of chemistry, and students readily get the feeling that nwriuns and syntheses are thr more p~drstrianaspects ofchemistry. We do students a hig disservice hy tench~ngthe principlesol suhsrances they do not recoenize.. mav never have seen. have not observed transformeiinto other substances, or have not prepared. Years ago I questioned the late Walter Hieber, the father of metal carhonyl chemistry, about the mechanisms of some of his reactions and syntheses. His reply was: "In my institute we do real chemistry (reactions and syntheses), not the philosophy of chemistry (bonding, mechanism, and spectra)." I would not go that far, hut I definitely recognize that chemistry is an experimental science and that "real chemistry" starts with reactions and syntheses. Almost all of our principles, including some of our sophisticated theories, are based on experimental observations. At best chemistry is an empirical science, with intelligent generalizations derived from exper. . iment. If you agree with the above, then it follows that we must teach our students reactions and syntheses. This is not easy because there are more than 100 elements, each with individual properties. For some of our teachers who were taught mostly the "philosophy" of chemistry it is particularly difficult to do this. Yet it is possihlel.2 to teach reactions and syntheses in inorganic chemistry, and this is being taught in organic chemistry. I am asked not to discuss here the technique of teaching reactions and syntheses, only the reasons why it is i m ~ o r t a nthat t this he done. There are perhaps several reasons for teaching reactions and syntheses, but let us agree that these may differ depending on whether the student becomes a professional chemist or takes only some beginning courses in chemistry. First, I believe that both types of students should he taught reactions and svntheses before thev get too far alone with orincioles. This teaching must be accompanied by lecture demonstrations and hands-on laboratory experiments. Here i t is merely the case of potting the "horse hefore the cart." Students should not be asked to learn principles in a vacuum. They should first see, feel, and smell these substances, and watch them react.
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In planning a chemisby ~ u r r es, m of me most impwtant decisions a teacher must make involve Me selection of matwial to be wvered and Me time to be devoted to each topic. For each column in this series,a high schwl and a college teacher have been invited todiscuss why they feel a perticular topic is impatant and how it wnbibutes to Me s M e n h '
understanding of chemistry.
' Basolo, Fred, J. CHEM.EWC., 57, 45, 761 (1980).
Basolo, Fred, and Parry, Robert W., J. CHEM. EDUC.,57, 772
119801 B ~ O I O Fred, , J. CHEM.EDVC., 54,257 (1977). 'See the news article in Chem. & Eng. News, 29 (11 October 1982). Shriver, Duward F., Chem. & Eng. News, 2 (22 November 1982). p.
2.
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Journal of Chemical Education
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in which chemistry fits into each one's life. This is the underlying reason that descriptive chemistry must fit into the daily chemistry lesson by design, and not by accident. Some Parting Remarks Since I was specifically charged not to mention pedagogical methods that 1employ to teach descriptive chemistry, I will address that topic in a later article. Succinctly put, there ate four underlvinereasons for ~ u t t i "n descri~tive e chemistrv into " the main chemistry curriculum: (1) Theoretical chemistry without some carefullv chosen descrintive chemistrv is not real chemistry. (2) ~ e s c i i ~ t i vchemistry e coupled 4 t h proper theory makes for relevant chemistry. (3) Heavy emphasis on principles and theories leaves students without an appreciation for the chemistry that is all around them. (4) There must he a balance as well as a synthesis of facts and theory in all chemistry courses. I feel that doing any less than these would be a real disservice to my students. If I have caused you t o rethink vour balance between fact and theory, then this short article ail1 have been a success.'
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Darrell H. Beach The Cuiver Academies Cuiver. IN 46511
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Many of the ideas presented in this paper grew o m of the Conlerence on Introductory Chemistry, New Directions In The Chemistry Cunicdum, which was held at McMaster University. Hamilton, Ontarno.
Canada. June 1978.
Dane11 H. Beach is Master lnshuclw and b i d e r of the Eugene C. Eppley Chair of Chemistry at the Cuiver Academies. He earned his BA in dremisby horn Central Michigan Univerrity. his MA f m m h Universiiy of Michigan, and his DEd horn University of S d a . AbUm of three books and numerous publications, end ediiw of the Chemical of the Monthfeahnein THIS J-NAL Beach has beena participant in numwous activities involving chemical education far more than 20 years. He received me Outstarding Chemisby Teacher foiw Stale of lrdiana Award from Purdue Section of the ACS was me~ Midwest~ re. mp ~. . ~ ~in 1977 - and~ gmnal recipient ol hMCA Cata ysl Award in 1979. Immediate Past Presldenl of the ACS. Fred Banolo 0s Monism Rol e s w of Chemmq a! Namwestm Unrvwslfy he eamej h 5 B Eo hom ~
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The student destined to become a chemist should surely be knowledgeable about certain basic reactions and syntheses. The student should know reaction types and trends in the periodic table in order to make intelligent guesses as to specific reactions and syntheses. An art historian would rapidly lose credibility if, when asked who painted the Mona Lisa and during what period, he said: "I don't know but I could look it up and tell you later." 3 The same would be true of a chemist who, when asked by a layman how to make copper or steel from their ores, and how baking soda and other common chemicals are manufactured, had to go look up the answer. I t is also important for chemists to know enough reaction chemistry that they not dostupid things which may endanger life and property, as happened recently a t one of our best uni~ersities.~ Students who will not become chemists should experience reactions and svntheses, hecause this may he all that thev will remember a b o k chemistry. Years afteFhaving had a chemistrv course. nonchemists recall nothing about the orincides rotten egg smeil of taught. w h a t most of them recall is H2S,the explosion of an ignited hydrogen + oxygen balloon, and the intense beat of the thermite reaction. I have been told this by lawyers, business persons, and others a t cocktail parties, committee meetings, and elsewhere. My remark to these people is, "Aren't you lucky you took chemistry when they were still teaching reactions and syntheses?"
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Fred Basolo Northwestern University Evanston. IL 60201
Southern Illinois University and his MS andPhD in Chemistry from lhe University of illinois. Co-author of two seminal teds, "Mechanisms of Inorganic Chemistry" and "Coordination Chemishy." Basola has over 300 scientific publications to his wedit and has served as editor of num e r w ~journals. He has a distinguished remrd of leadership in hACS. sewice on scientific paneis. and lectureships ail over the wwld. A member at the National Academy of Science. Basolo won the ACS Award f w Research in inwganic Chemistry in 1964, was the first r e ciDient of lhe Baiiar Medal Award in 1972, wan the ACS Award for Dislong~sned Sewlce in n0rgan.c Cnemislry m 1975, an0 wan the James F ac* Norrls Auard for Odslanding Acnievamenl in the Teachmg ot Chemistry ln 1981
Volume 61 Number 6 June 1984
521
