Chemical Education in American Institutions
The Metcalf Chemical Laboratories
many years teachers of chemistry have felt a need for a major revision in the chemistry curriculum in our colleges and universities. This has been expressed in their general dissatisfaction with the first year of college chemistry and their dilemma upon attempting to introduce new material into the already overcrowded syllabi. A general lack of emphasis on inorganic chemistry and, indeed, a lack of interest for inorganic research (with the notable exception of that on nuclear fission products) has been evidenced by the small number of graduate students who elect research problems in this field (1). Interest in analytical chemistry among students is also less than it should be. Evidence of this dissatisfaction lies in the large number of papers and symposia recently devoted to the teaching of general chemistry in college (2-15) and to the ever increasing number of textbooks in general chemistry. Freshman teachers professing to emphasize the "princiFOR
A NEW PROGRAM FOR TEACHING THE FUNDAMENTALS COLLEGE'
OF
CHEMISTRY
IN
JAMES S. COLES, LEALLYN B. CLAPP, AND ROBERT P. EPPLE Brown University, Providence, Rhode Island
ples" of chemistry are often merely attempting to give a watereddown physical chemistry course to students as yet unprepared mathematically for a useful course in that field. Pedagogy in analytical chemistry has also been a field for open debate. No one will, deny the im-
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Presented before the Division of Chemiod Education at the 113th meeting of the American Chemical Society, Chicago, Illinois, April 19, 1948.
JANUARY, 1949
portance of analytical chemistry to the other branches of the science, but the methods of teaching it a d its specific place in the college curriculum have been subject to question, and, unfortunately, the answer has often been to deemphasize analytical chemistry or limit the time devoted to it. The colleges generally fail to make use of the chemistry taught in secondary schools (14-30). College people are prone t o say that secondary school chemistry is not taught from a rigorous or modern point of view; they prefer to have a student come to them with no previous training in chemistry so that he will not have to unlearn wrong concepts previously acquired. The practice of pooling all students in the same introductory course in college chemistry without regard to previous training is followed by many institutions, and must be considered as further evidence of their disregard for secondary-school chemistry. Even in institutions where separate courses are maintained they are often so nearly identical as to belie the necessity of separation. Because the colleges repeat much of the same chemistry that has been taught in the secondary-school course, the secondary-school teachers justly say, 'What's the use of our offering chemistry at all if the colleges are going to teach the same material again?" The two courses which seem relatively free irom these criticisms are organic and physical chemistry. The sequence in which the various fields of chemistry have been presented in college is apparently the result of historical accident rather than logical planning (21). Chemistry was originally a part of natural philosophy until it grew to such proportions that it was necessary to segregate it. As the subject of chemistry itself grew in size, the various branches were separated from one' another. While Berzelins was laying the foundations of inorganic and analytical chemistry, Liebig was giving the first laboratory instruction in organic analysis. The preparation of urea from inorganic sources in 1828 hastened the separation of the chemistry of carbon compounds as a unique study. In spite of the influence of Berzelius, systematic instruction in inorganic analytical chemistry was not given until several decades later; courses in physical chemistry were rare until after 1900.2 The segregation of physical chemistry left inorganic chemistry for the introductory course. But inorganic chemistry itself progressed, due in part to the application of physicochemical techniques for the description and measurement of the properties of inorganic suhstances and for the understanding of chemical phenomena. Hence the instructor in the beginning inorganic course found himself devoting a substantial portion of his time The courses taught in college paralleled this historical devclopment of the soience, a t least partially. At Brown University, the ohemistry laboratory was first opened to students in 1853, although lectures in chemistry had been given for s t least five y e a s previously. In 1865 the catalog reads, "It is the design of the department to teeoh students analytical chemistry and then to direct their studies to practical applications of chemistry." Qualitative and quantitative analysis were listed as separate courses in 1874; orgenio chemistry was offered with that title for the first time in 1880 and physical chemistry in 1901.
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to the concepts of physical chemistry which necessarily precede the understanding of inorganic chemistry (22). The same thing became true of qualitative analysis with the introduction of dissociation and other equilibrium phenomena. Considerations of coprecipitation, the theory of indicators, and instrumental methods are examples of the manner in which physical chemistry entered the course in quantitative analysis. This led to the situation which exists in many colleges and universities today, where a diluted version of physical chemistry is taught in the course in general and inorganic chemistry, is continued in the courses in qualitative and quantitative analysis, and finally, after the student has acquired sufficient background in mathematics and physics, it is repeated and extended more rigorously. Such repetition might not be considered extravagant were it not that more and more topics must be crowded into the existing courses as chemistry advances t o new frontiers. What the authors and their colleagues hope to do in the program inaugurated a t Brown in 1948-49is to give their students a thorough grounding in the fundamentals of chemistry during the freshman and sophomore years and then, in the junior and senior years, allow them a small degree of specialization in one or two particular fields, such as analytical, organic, physical, inorganic, industrial, or biological chemistry. In chemistry, the need for compartmentalization of subject matter is rapidly disappearing, as exemplified by physical chemists working on problems ranging from those of electron diffraction to antibodies, organic chemists studying reaction rates and mechanisms, biochemists synthesizing organic compounds, to mention only a few. Why not, then, present the fundamentals of chemistry in a sequence of courses to be taken during the first two years of college (the "lower" college)? These courses would cover the introductory topics of physical, organic, and inorganic chemistry, and would include considerable experience in the techniques of analytical chemistry. The student will be prepared to elect during his last two college years (the "upper" college) advanced courses in more specialized branches of chemistry (which will include a required course in analytical chemistry). Perhaps the most logical order in which to present the fundamentals of chemistry would be for the introductory course to consist of the subject matter usually found in physical chemistry, since the concepts of inorganic and organic chemistry can well be based on physical chemistry. Usually this is not practical, since the average college freshman does not have the background in mathematics or in physics requisite for the best understanding of physical chemistry. The earliest point a t which physical chemistry can be introduced efficientlywill ordinarily be a t the beginning of the sophomore year, after the student has taken a year of college mathematics (which would include differential calculus) and a year. of college physics. The alternative, therefore, is for the first year course to include the most valuable part of chemistry that can be
taught with the least physical chemistry as a prerequisite. In the new Brown program the first two semester courses (I and 11) in which the student enrolls in his freshman year concern themselves mainly with reactions of a limited number of elements and compounds of carbon, hydrogen, nitrogen, sulfur, phosphorus, and the halogens. Although courses I and I1 include a major port,ion of t,he subject matter now presented in the introductory course in organic chemistry, this is not equivalent to placing college freshmen in the regular organic chemistry course. That has been attempted previously with varying success. The usual organic course assumes a greater maturity and chemical background on the part of the student than the a.verage freshman possesses. Courses I and I1 are given at the freshman level rather than a t the level of the upperclassman. They are not necessarily restricted to organic chemistry, nor will the second year courses be restricted to physical or inorganic ~hemistry.~The introduction of Course I considers, from an elementary point of view, the atomic structure of the few elements mentioned, the types of bonds which these elements can form, the method of forming them, and the nature of the compounds so formed. Following this introduction, much of the material of classical organic chemistry is discussed, but with other concept,^ introduced and studied where necessary. In addition to the essentials of atomic structure such topics include acids and bases (limited to the elementary concepts required for beginning organic chemist.ry) and oxidation-reduction. The laboratory work accompanying these courses is again adapted to freshmen, and in the beginning emphasizes the various operational techniques of chemistry, such as glassworking, distillat,ion,crystallization, filtration, extraction, sublimation, the determination of melting points and boiling points, rough weighing and volumetric techniques. The usual experiments of organic chemistry are not undertaken until after some skill in laboratory techniques has been acquired. ParalIeI with these courses during the freshman year; college physics and mathematics are required. During the sophomore year, in addition to continuing mathematics, three semester courses in chemistry will be required, Course I11 during the first semester, and Courses IV and V concurrently during the second semester. Course I11 will assume and take advantage of the year of general college physics, including such subjects as the kinetic theory of gases and the gas laws, electricity and magnetism (and the electromag netic spectrum), acoustics, mechanics, optics, elementarv uarticles, and nuclear structure. The course will openAwith consideration of elementary quantum
a
Wnfortunately, due to the absenoe of 8, more adequate common terminology, it is necessary to use the terms organic, inorganic, and physical in describing various aspects of these courses. Actually, it is hoped that these barriers will be completely broken down. The catalog titles for the five basic introductory courses comprising the first two years are 'c~undamentalsof Chemistry, I," "Fundamentals of Chemistry, 11," etc.
theory, leading into atomic structure and its relation to the periodic table, and from there to molecular structure. The remainder of Courses I11 and IV will consist for the most part of the subject matter of the classical course in physical chemistry, assuming the student's background in elementary physics, and introducing such other areas of chemistry as may seem desirable. (For example, the quantitative treatment of equilibrium, dissociation, and hydrolysis will be covered in greater detail than is the case a t present.) This particular order of presentation for Courses I11 and IV is followed for two reasons: (1) the mathematics required in the first part of the course will be mainly algebra, thus giving more time for the study of calculus before it is used; and, more important, (2) atomic and molecular structure, and the periodic tahle, will have been studied prior to the beginning of Course V, which will be concerned for the most part with inorganic chemistry. The laboratory for Courses I11 and IV will develop skill in refined weighmg and volumetric techniques, and at the same time will introduce the instruments and techniques of physical chemistry. The subject of inorganic chemistry will he the con. tent of Course V in the second semester of the sophomore year. It will be assumed that the student has a rather mature knowledge of atomic and molecular structure, the covalent bond, and the concepts of physics and physical chemistry, such as electrode poteutials, ionization potentials, electrical and thermal conductivity, phase transitions, and the gas laws. All of these will be available as tools for teaching inorganic .chemistry on a more advanced level than the beginning course a t present. The laboratory work in inorganic chemistry can also be of a more advanced nature, since many laboratory skills and techniques will be available to the student. For example, the preparation of compounds of different oxidation states of manganese can be combined with quantitative studies of the effect of acidity on their &ability and oxidizing properties; the effect of ionic strength and complexformiug ions on the ferrous-ferric equilibrium can be studied by potentiometric methods; some experiments can be performed in nonaqueous media, e. g., liquid ammonia. The new program for the lower college is given in Table 1. TABLE 1 New Program for the Lower College ----Freshman Semester I
YearSemester I1
Chemistry I Mathematics Physics English Eloctive
Chemistry I1 Mathematics Phys~cs English Elective
-----Sophomore Semestw I Chemistry 111 Mathematics Elective Elective
Year---Semester II Chemistry IV Chemistry V Mathematics Elective
The electives will probably be in foreign languages until proficiency is established. This foundation provided by the five courses in the
JANUARY, 1949
fundamentals of chemistry offered in the lower college will provide a good background for the course in analytical chemistry and will permit the election of a wide variety of advanced courses during the student's junior and senior years. These will be selected from either a one-semester course or a one-year course in one or more of the following special fields: organic chemistry, which would be a semester of qualitative organic analysisandasemester of advanced preparations or advanced theory; inorganic chemistry, which might include radiochemistry, tracer techniques, etc.; physical chemistry, including such subject matter as classical and elementary statistical thermodynamics, and modern theory and experimental methods in molecular structure, kinetics, and similar topics; biochemistry; industrial chemistry or acourse in chemical engineering. Through elections from these advanced offerings, any inadequacy of training in organic or physical chemistry taken in the lower college will be more than compe'nsated. It will be noted that analytical chemistry now has physical chemistry as a prerequisite, rather than vice versa. The program in chemistry.for the junior and senior year is summarized in Table 2. TABLE 2 New Courses for the Upper Collese Required: Andytical Chemistry A Andytical Chemistry B Elective: Physical Chemistry A (chemical thermodynamics) Phvsieal Chemistry B (molecular structure, reaction rate (hexy, photocheinistry) Organic Chemistry A (~dentificrttionof organic compounds) Organic ChemistryB Industrial Chemistry A and B (unit operationd Inorganic Chemistry A (radiochenustry) ~~~~~~~i~ r!hmmiqtrv R -..u.-.-..d Biochcrnistry
-.."
The one topic in chemistry as it is now taught which is conspicuously absent in the new Brown program is the systematic scheme of qualitative analysis. The function and usefulness of such a scheme of analysis is today subject to much question. The number of different elements usually studied in current courses is limited, and even for the elements which are included,
13
In the Advanced Anslytical Laboratory
the application of the scheme of analysis in actual practice is infrequent, to say the least. Probably the most common argument put forward for retaining the systematic scheme of analysisin the college chemistry curriculum is that it is the one course where the students really learn inorganic chemistry. If this is the most cogent argument for retaining this scheme of analysis, it seems reasonable that inorganic chemistry might be even better taught in a course and laboratory specifically designed for the purpose (33). The old type of general chemistry laboratow course, with one or two exceptions, is probably the weakest of all laboratory courses. The replacement of this laboratory by one in rigorous inorganic chemistry, using the most modern techniques, should be much better. It must be reiterated that less time will not be spent on analytical aln.t,er chemistrv. Instead the time mill be utilized at, -. ..... date in the student's career' One great advantage of this curriculum is that i t takes cognizance of the precollege course in chemistry. By not repeating high-school chemistry the level of student interest will be higher. The students will not assume that thev already know the subiect. lose interest, and fail toapply themselves until, too iate, they find out that college chemistry does require some effort on their part. Also, in making the transition from secondary school to college, which is difficult for many students, the chemistry course, although covering new material, will continue to be descriptive rather than quantitative in nature throughout the freshman year, ~
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JOURNAL OF CHEMICAL EDUCATION
14
as was the secondary school course. Greater knowledge of, and interest in, inorganic chemistry should also result from this curriculum. Students taking this new program a t Brown University are those who are candidates for the degree of Bachelor of Science in Chemistry. They constitute a rigidly selected group of students whose interest in chemistry is already sufficiently great before entering college that they are fairly sure they want to major in this subject. Most of these students present entrance credit in chemistry. Those who do not will be required to pass a proficiency examination in chemistry, or, failing this, to take the introductory course in chemistry which is given for liberal arts students, and enter this program in their sophomore year. Such students are delayed one year in entering the new program, but ample opportunity for making this up is afforded in the senior year. Many difficulties, bbth foreseen and unforeseen, will be encountered in the early years of this program. Among those anticipated or pointed out by others are: lack of textbooks, transfer students, sufficient carryover from physics, heterogeneity of level of secondary school training, and the ultimate assimilation of premedical and nonchemistry students into a part of the program should it prove successful for the specialized group for which it was designed. Of the several medical schools which have examined the prospectus .of this new program, the comment has been uniformly -favorable with regard to its desirability in premedical -training. Another correspondent is enthusiastic over 'the possibilities of the first two courses as the basis of a "cultural" course for nonchemists. Among the most important advantages of this program is the teaching of modern structural concepts in terms of the structures and properties of the first row elements, where the application is relatively simple,
rather than in the field of inorganic chemistry (24). Such difficult topics as ionic compounds, variable valence, ionization and electrode potentials, complex ions, and amphoterism would be postponed until the sophomore year, following the course in physics and concurrent with the latter part of the course concerned mainly with the topics of physical chemistry. Equally with the authors, the other members of the Department of Chemistry a t Brown University, as well as many friends elsewhere, have contributed to the development ofthis program. I t is hoped that the results of the program may be some compensation for their contributions. LITERATURE CITED (1) Rocnow, E. G., J. CHEM. Eouc., 24,490 (1947). (2) CLARK, W. M., Johns Hopkins A l u m n i Magazine, 24, 235 ( 1-9RR\ - -,. (3) CONKLIN, R. B., J. CHEM.EDUC.,24,269 (1947). (4) DUNKELBERGER, T. H., ibid., 24,381 (1947). (5) FLETCHER, C. J. M., School Sci. Rev., 23,282 (1942). I. D., J. CHEM.EDUC.,11,650 (1934). (6) GARARD, W. C., ibid., 13,423 (1936). (7) JOHNSON, i8) KEIGHTON. W. B.. ibid.. 22.45 (1945). isi MEYER.M.. i b i d . . ~ 325.336 ~. (i945): (ioj PERRY,'R. j., ibid., 22,497 (19'45). (11) STANDEN, A., ibid., 22,554 (1945). (12) WAKEAAM, G., ibid., 11, 609 (1934); 12, 68 (1935); 24, 247 (1947). (13) WILDMAN, E. A.,ibid., 12,11(1935). F. G., ANDP.A. LEIGHTON, ibid., 13,437 (1936). (14) ANIBAL, P. E., ibid., 15,285 (1938); 16,510 (1939). (15) CLARK, J., AND G. D. STODDARD, ibid., 6,85 (1929). (16) CORNOG, A. B., ibid., 25,24 (1948). (17) GARRETT, (18) GLASOE, P. M., ibid., 10, 571 (1933). (19) GRADY, R. I., ibid., 6, 82 (1929). (20) HERRMANN, G. A,, ibid., 8, 1376 (1931). R. J., ibid., 6,1126 (1929). (21) HAVIGHURST, (22) MARTINETTE. M., SchoolSci. Math., 40,808 (1940). (23) HILL,G. A,, J. CREM.EDUC.,6,914 (1929). W.,ibid., 18,439 (1941). (24) HERED. \
