MARCH, 1955
REDUCING DUPLICATION IN HIGH-SCHOOL AND FIRST-YEAR COLLEGE CHEMISTRY "GROUP A.'"
SCHOOL AND COLLEGE CHEM-
ISTRYTEACHERS MEET~NGA T -KENYON COLLEGE. GAMBIER. OHIO. JUNE 26-JULY 2. (Prepared b y Leallyn B. Clapp)
T H E question, "Why do you repeat so much?" ( l a ) asked of the college teacher, has been debated publicly (lb) a t least onre, privately unnumbered times by high-school and college teachers of chemistry, and in print several times over the last thirty years. Another vigorous and forthright indictment of the college position is given by Glasoe (#), the tone of which is suggested in the title of his first paper, "The deadly parallelism between high school and college courses in chemistry." The best defense of the college position is probably given by Ehret (3) under the title, "What I wish I could count on" ( I h ) . Ehret suggest,ed placement examinat,ions as t,he feasible way out of the dilemma. Since the colleges hare not found uniformity in what they could count on, many have done nothing to recognize a good job in the schools, and consequer~tly the high-school teachers have never felt satisfied. I t is probably fair to say that many college tteachers never believed their own arguments, especially in view of the accumulated evidence that high-srhool chemistry is an important aid to success in college chemistry (4-10). i'ievertheless, the two groups studying the "Iiiterrelation of high-school and freshman college chemistly" a t Kenyon College in the fifth annual Conferenre on General Chemistry did not agree on the fundamental issue of duplication. "Group B" mas "not seriously 1
Authors listed in last paragraph.
concerned about the alleged danger of repetition for pupils who go on to college. The serious college student will surely profit by a reasonable amount of repetition." "Group A," on the other hand, suggested that "the subject matter of chemistry is so extensive that it should not be difficult to find material of value to the high-school student which is different from that given in first-year college, which will be interesting and stimulating both to those who go on to college and to those who do not, and which mill give a solid background as a basis for the further thinking of the student in chemistry." The concern of "Group A" culminated in suggesting the study of the chemistry of carbon compounds in high school with the introduction of enough fundamental concepts based on the chemistry of ot,her elements to make this possible. This suggestion to avoid overlappiug in high-school and college chemistry does not appear in the literature (11-15) although a t least one schooPhas offered organic chemistry for many years, apparently as a second course. While many high-school and college general chemistry courses now contain sufficient organic chemistry to give an appreciation of the multiplicity of carbon compounds, this was not the philosophy behind the suggestion of "Group A," Instead, the entire course mas to be centered on the chemistry of carbon com-
'
Central High School, Philsdelphirt, Pennnplvsnia. Sce H. J. ABR~HAMS, J. CHEX.EI)uc.,24, 244 (194i).
JOURNAL OF CHEMICAL EDUCATION
142
pounds and no inorganic substance was t,o he intmduced except when it wan necessary t,o nnderst.and the chemistry involved. SUGGESTED COURSE
With this in mind, "Group A" suggested the following course outline or list of chapter headings as a possible guide to accomplishing this end. The order is not meant to he rigid. (One member of "Group A" suggested that Chapter 7 should follow Chapter 4.) Chemistry of Carbon Compounds for High Schools 1. Atoms and molecules (Gay-Lussae, Avogadro, Dalton) 2. Formulas, moleeuler weights, equations 3. Structure of the atom 4. Bond formation (types, rule of two, rule of eight) 5. Rertotions (chemical change, inertness, energy, etc.) 6. Solids, liquids, gases (structure, separations, solubility, etc.) 7. Periodic table 8. Carbon, combustion 9. Homologous series, alkanes 10. Alkenes, alkyl halides 11. Alkynes 12. Alcohols and water 13. Ethers 14. Funotional ggrup isomerism, structursl proof of an organic compound 15. Acids and esters 16. Aldehydes and ketones 17. Oxidation-reduction 18. Amines and ammonia 19 . Acids and banes -~ -20. Nitro compounds 21. Aromstic hydroearhans 22. Stereoisomerism(evidence and proof of tetrnhedrnl structure of carbon atom) 23. Carbohydrates 24. Amino acids and proteins
It was anticipated that Chapters 1 to 7 would take approximately 13 weeks in a 36- or 40-week year and Chapters 8 to 24 the remaining time. While the chapter on aldehydes and ketones itself could be made to last four or five weeks, it appeared desirable a t least to reach the point where the influence of one functional group on another (carbohydrates, amino acids) could be contemplated. The chemistry of a t least ten functional groups seemed a minimum for an appreciation of organic chemistry. The existence of a family of organic compounds might be introduced with the following hypotheses: (a) carhon always has four bonds; and ( b ) carhon may be joined to other carbons in single, double, and triple bonds. These hypotheses would receive some defense in Chapter 14 and he rigorously proved in Chapter 22. There are more defensible ways of introducing the tetrahedral carbon3 but this suggested 8 From a geometric viewpoint, the properties of a tetrahedron and joined tetrahedra could be deduced. The deductions shout isomeric carbon eompounds could then be proved congruent to the deductions made about the geometric figures themselves, hut this method appears rather abstract for high-school students. LP, h y s i c ~ t h Elements," e As long ago as 1920, N. R. C ~ P B E L " Cambridge University Press, London, p. 225, suggested that the study of chemistry might well be started with stereoisomerism.
method takes into account the principle of economy of explanation. Some of the danger inherent in building a house before the foundation is laid ran scarcely be avoided in any beginning course if the first chapter is not interminably long. The order of presentation of the chemistry of functional groups (Chapter 9 and succeeding ones) was suggested as follows: nomenclature, preparation, physical properties, chemical properties, uses. The emphasis on particular chapters would, of course, depend on the taste of the teacher. Attention is called to the fact that the chemistry of alcohols and water and amines aud ammonia could be presented concurrently, a desirable procedure. The difference between oxidation number and covalence (valence) is much easier to put across with organic examples than with elements involving variable valence. Balancing oxidation-reduction equations with organic compounds as reducing agents and a limited number of inorganic oxidizing agents has been found to give students more confidence in their own ability to handle this type of exercise than the use of inorganic examples alone. ADVANTAGES
While the suggested course includes the fundamental concepts desirable in a terminal course as well as in a college preparatory course, it has the following additional advantages: (1) A stimulus to the high-school teacher is provided by a fresh approach to chemistry and his enthusiasm will be reflected in heightened student interest. The cream will not have been taken off the beginning course for the college teacher by the highschool teacher who has done a good job. ( 2 ) Emphasis of size and shape as important factors in chemical reactions is made in carbon chemistry. It would be well to have this emphasis before the student reaches general chemistry where these factors are now recognized as increasingly important. (3) Carbon chemistry can offer numerous and interesting examples of substances met in daily life, e. g., plastics, medicinals, fibers, dyes. (4) Molecular properties of acids such as HONOz, S02(OH)*, and CHaCOOH are emphasized previous to their ionic properties. Some mistaken notions about properties of acids can thus be circumvented. (5) Some pitfalls of variable valence are avoided. (6) Although arithmetical problems could and should he included, the student who is frightened of numbers would be less seriously handicapped by the proposed course than by the conventional one. Problems involving the number of isomers in any homologous series of a given chain length should prove fascinating even to a sophisticated high-school student; problems in stereoisomerism should be intriguing. (7) Thought and careful control in laboratory experiments are required; experiments are not the "filling-in-the-blank" type of exercise.
MARCH, 1955
143
OBJECTIONS
AUTHORS OF THE REPORT
The members of "Group A" foresaw certain objections t o the proposal but anticipated a t least partial answers to these objections. (1) Duplication is simply shifted to a more advanced level. College organic chemistry is now taught largely from the point of view of reaction mechanisms and, therefore, the duplication is more apparent than real. In any case, the over-all duplication would be less, since the number of students reaching organic chemistry in college is much smaller than the number taking general chemistry. (2) The plan might involve additional expense and new equipment for the laboratory. Experiments using semimicro techniques might obviate the need for certain special equipment and reduce the cost of glassware. (3) No quantitative work is afforded. Quantitative experiments are available for such a course, e. g., the Dumas molecular weight determination, neutralization equivalents, and others in addition to some traditional quantitative experiments which could be offered in the first part of the course. (4) There may be increased danger from fire. While the danger is recognized; careful choice of experiments, the use of semimicro techniques wherever possible, and general care on the part of the instructor would minimize this aspect. Of course, some inorganic experiments are also dangerous. (5) No suitable textbooks and manuals are avail-
The original report was prepared by "Group A," studying the "Interrelation of high-school and freshman college chemistry" a t the Central States Session of the fifth annual Conference on General Chemistry sponsored by the Committee on Teaching of College Chemistry of the Division of Chemical Education of the American Chemical Society at Kenyon College, Gamhier, Ohio, June 26-July 2, 1954. The participants in "Group A" (listed below) were six highschool and seven college teachers of chemistry who chose this topic for discussion a t the Kenyon College Workshop. The report was redrafted for publication by Leallyn B. Clapp, to whom requests for reprints, criticisms, and suggestions may he sent.
able ...~-
LImFSTURE CITED
If the suggested course is worth while, texts and would be forthcoming. lLNew" courses are always given first without formal texts. (6) Teachers are not qualified to offer such a course. The course will admittedly not be of interest to all high-school teachers of chemistry and would not be feasible for others to try. Many teachers are properly qualified, however, and should he encouraged to try the "experimental method" on a high-school course in chemistry. After the meeting at Kenyon College, one member of "Group A" in discussion with his colleagues a t Ohio State raised another objection: (7) ~h~ first course in should not be such a small fragment of the science, that is, the chemistry of one element (carbon) regardless of the importance of that element.
( l a ) GIFFORD, D. W., J. C ~ MEDUC., . 26, 50 (1949). (lb) Tenth Summer Conference, N e w England Association of Chemistrv Teachers. Universitv of Maine. Orono.. August 26, 1948. (2) GLASOE,P . M . , J. CHEM.EDUC.,6, 505 (1929); 10, 571 (1933); 15, 14 (1938). ( 3 ) EHRET, W, F,,ibid,, 25, 699 (1948), ( 4 ) TAOMSON, E. w., ibid., 30,353 (1953). . (5) HADLEY, E. H., R. A. Scorn, AND K. A. VANLENTE,ibid., 30, 311 (1953). ( 6 ) CLARK, P. E., ibid., 15, 285 (1938); 16, 510 (1939). (7) C U R R ~ R A., J., ibid., 8 , 328 (1931). F, E,, ibid,, 3, 301 (1926), (9) CORNOD, J., AND G. D. STODDARD, ibid., 6 , 8 5 (1929). (10) STEINER, L. E., ibid.. 9, 530 (1932). (11) ANIBAL, F. G., AND P. A. LEIWITON, ibid.: 13,137 (1036l (12) BURT.C. P., ibid., 5 , 990 (1928). (13) CLARK, A. J., ibid., 0 , 99 (1932). (14) G ~ ~R.~I.,Yibid., , 6 . 8 2 (1929). (15) GARRETT,A. B., ibid., 25, 24 (1948).
James M. Babbitt, Ohio State University, Columbus, Ohio. William E. Cadhurv. .. Jr... Heverford College, - . Hrwerford. Pennsvlvania. Ledlvn B. C l a o ~ Brown . Universitv. Providence. Rhode Island. Carl kngels, School, West& ~ i e h i g a dCollege, K a l a maaoo, Michigan. Herman Freymiller, Union Free High School, Eagle River, Wisconsin. Garth Keller, Gamhier High School, Gambier, Ohio. Alhertine Krohn, University of Toledo, Toledo, Ohio. Helen G. Lenta, Eastern High School, Baltimore, Maryland. Arild Miller (Chairman), Carlton College, Northfield, Minnesota. L. A. Pappenhagen, Mount Union College, Alliance, Ohio. Marshall S. Smoler (Secretary). Tilden High School, Chicago, Illinois. Luke E. Steiner, Oherlin College, Oherlin, Ohio. Fred Watts, Circleville High School, CircleviUe, Ohio.
