Enno Wolthuis Calvin College Grand Rapids. Michigan
I I
Organic Chemicals for Everyone A course for the nonscience sfudsnf
In recent years there has been a flurry of activity to relate chemistry to the nonscience student and to the general public. There are various ways to do this, and colleges have intmduced new courses to achieve this objective as reflected in the many articles in this J o ~ r n a l . ' . ~ In our college, too, we have tried to convey the spirit and value of chemistry in a variety of Interim courses, one of which is "Organic Chemistry for Everyone," or "Organic Chemistry in Daily Life." (Our apologies to the inorganic chemist; no offense is intended.) We describe this course briefly, together with some reflections on its reception. The emphasis in this course is on the practical significance of organic chemistry in our culture, and the historical development of organic chemistry as related to economic and political events. More specifically, the objectives were to show 1) how the organic chemist converts the raw materials of nature into useful synthetic products 2) our dependence for the majority of produds on petroleum 3) haw the development of organic chemistry has radicallv altered our wav of life. but also how
our society
6/I
4) where applicable, some of the ecological imnlications of the use of synthetic organic
The general outline of the course is as follows I.
11.
111. IV.
Organic Chemicals for Everyone Fundamentals of organic chemistry Types and reactions of organic compounds Chemicals from natural gas and petroleum Natural gas as raw material Petroleum refining developments Petroehemicals-produets derived from ethene, propene, butenes, benzene, toluene, xylenes Chemicals from coal Destructive distillation, coal tar chemicals Chemicals from plants and animals Carbohydrates,lipids, proteins
leum products was made with asurvey of changes in refining processes in response to the changing demands of internal combustion engines. As simple fractional distillation gave way to cracking, isomerization, polymerization, alkylation, and aromatization, the petroleum industry became an imnortant source of all kinds of chemicals oreviouslv obtainable only, if a t all, from coal. Special attention was given to the demands imoosed uoon the netroleum industw bv the second World War,'with the result& rise of the peirochemical industrv. Useful petrochemical derivatives were discussed in relation to their shn-tinpl materials as derived from oetroleum refining. namely, ethene, propene, butenes, benzene, toluene, and xylenes. In each case it was shown how such a simple compound, subjected to a series of reactions, is converted to familiar to all, such as plastics, fibers, food additives, rubbers, detergents, dyes, to name hut a few. Liberal use was made of flow charts (see fig.). The students found these charts very
mmene
ph e n d
in N ' mrema skin Cream
CI-c-CI
acetone
alycarbonate pkstios Pshields o? safety glasses and
(see also
chart 9) Salieylamjde in Exeednn CONK,
salicylic
Part I involved a brief historical survey of the subject, the tetravalency of carbon, I bonding, the types of compounds by functional NO2 groups, and, finally, a review of the chief types of reactions-oxidation, reduction, addition, and various types of substitution. Lecture demonstrations were used extensively to demonstrate these concepts. About one-half of the course was devoted to Part 11. This section began with natural gas, its composition, its oxidation products such as carbon, carbon monoxide and dioxide and the OH uses of these, its conversion to acetylene and the use of it to make all sorts of polymers, its halogenation to give such useful products as a paint removers, Teflon, silicones, dry-cleaning fluids, Freons, and many more. The transition from natural gas to petro- Flow chart. Petrochemicals from benzene. 636 / Journal of Chemical Education
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+ CH,COCH,
H*
Oil of wintergreen in ~irierine vicks3-;1
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p-aminophenol photo developer
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Phenaeetin in Bromo-Seltzer
helpful and instructive in tracing the flow from raw materials to final products. Many students expressed surprise a t finding how large a rale petroleum occupies in our civilization. Part I11 (chemicals derived from coal) hegan with a discussion of destructive distillation, its products and their uses. One of these, coal tar,then was treated more extensively with reference to charts showing derivatives from cresols (Lysol, BHT, etc.), naphthalene (detergents, colors, etc.), anthracene (dyes), pyridines (allergens, sulfa drugs, etc.). At this point in the course, we once again pointed out how the availability of useful chemicals, their sources and prices, greatly depends upon nonscientific events. For example, hefore about 1940 coal was our only source of arenes, and therefore of such products as Styrofoam, Tide, sulfa drugs, aspirin, etc. The demands made upon the chemical industry during the second World War changed all that, with the result that today we utilize petroleum to supply us with the larger part of these products, in greater abundance and a t lower prices. This may change radically if the petroleum shortage becomes acute. Part N of the course was devoted to our dependence on living matter for many necessary chemical products. Starches serve as raw material to give us such items as the dextrins for mucilages, dextrimaltose for infant feeding, corn syrup, sorhit01 for surfactants and vitamin C, and citric acid for heverages, to name hut a few. Among the cellulose derivatives we have cotton, the rayons, nitrocellulose for lacquers, and others used as food additives. Fats and oils are important for the manufacture of soap, shortenings, oleomargarine, food emulsifiers, synthetic detergents, and many more.
This summarizes very briefly the general nature of the course. As each unit was considered, the students were asked to list the chemical comoounds found on labels of nroducts they could find a t home i n in stores-drug, grocery, h'ardware, etc. These were then discussed with respect to their raw material sources and their derivation from these sources. At the end of the course students were asked to make a tabulation of al) of these, including in the tahle the trade name, ingredients, and the raw material source of each ingredient. This exercise, as much as any, brought home to them rather forcefullv our deoendence on natural materials, and the sianificant ;tile chemistry plays in converting them to usef& ~roducts.Even the admittedly disinterested students, who kere taking the course only to satisfy the physical science requirement, found this project rather intriguing and meaningful. Student reaction was generally favorable, enough so to warrant offering the course a second time. No doubt, many did not learn much organic chemistry. But most of them, judging from our requested evaluation, did begin to see that chemistry relates directly to the way they live and to the ~ r o d u c tthevdeoend s " . uoon everv -dav..Afew were fascinated enough to enroll in additional chemistry courses, and at least one student decided to undertake the chemistrv. maim Dro. . gram. Fahrenholtz, S.,J. CHEM. EDUC., 50,499(1973) and references therein. Trumbore, C. N., J. CHEM. EDUC., 52,451(1975)and references
therein.
Volume 53,Number 10, October 1976 / 637
