3
Literature Cited (7) MAHAN, B. M., "Elementary Chemical Thermodynamics," W. A. Benjamin Inc., New York, 1963. (1) KOKES, R. J., DORFMAN, M. K., AND ANDREWS, D. H., (8) NASH, L., "Elements of Thermodynamics," Addison Wesley J. CHEM. EDUC., 39, 16 (1962). Publishing Company, Inc., Reading, Massachusetts, (2) KOKES, R. J., DORFMAN, M. K., AND MATHIA, T., J. CREM. EDUC., 39, 18, 20, 90, 91, 93 (1962). 1962. (3) "Editorially Speaking," J. CHEM. EDUC., 38, 333 (1961). (9) HELLER, L. A,, AND HERBER, R. H., "Principles of Chem- (4) STEINER, L. E., J. CHEM. EDUC., 38, 490 (1961). istry," MoGmw-Hill Book Co., New York, 1960. (5) BENT, H. A,, J. CHEM. EDUC., 39, 491 (1962). (10) BROWN, T., "General Chemistry," Charles E. Merrill Books, (6) BURTON, M., J. CFIEM. EDUC., 39,491 (1962). Inc., Columbus, Ohio, 1963. G. R. Bakker, 0. 1. Benfey, I W. J. Stranon, and 1. E. Strong Earlham College I The Earlham Chemistry Curriculum Richmond, Indiana Time was when individuel chemists were broadly aware of developments over the whole of the eoienoe. True, the division of chemistry into organic, inorganic, physical, and anrtlytied ~sectians is of very long standing, but specialists in any one of these used to be an familiar terms with the others. But that time has long passed, thanks mainly to the explosive growth of our science during the past 50 years and the fantastic increase in factual knowledge that bas accompanied it. The practitioners of the various branches have drawn more and more apart with the passage of time, and only a few yeaxs ago the average organic chemist's knowledge and familiarity with, say, physical chemistry effectively terminated a t the under- graduate level. But within chemistry, just as in science ss a whole, most of the major developments me now occurring in the borderland areas between the traditional divisions, and we can therefore no longer live happily segregated if we me to progress further. This, of course, poses s real problem in the education of the chemist. The plain truth is that we must re-think the whole matter of training courses and the traditional divisions of the science on which our university and college courses have been based. This is no easy matter I know, but we must all apply ourselves to it and to the related problem of the ancillary subjects of study, for chemistry is also advancing in the borderlands be- tween it and, for example, the biological sciences.' For the past seven years at Earlham College we have been puzzling over the problem of developing an ef- fective M resent at ion of chemistrv to undereraduates. Our iniGal plan was described in"1958.~ hi essential feature of the plan for a four-year curriculum was that Presented as part of the S,ymposium on Reoent Trends in Under- eraduate Curricula before the Division of Chemical Educetion st ;be 145th Meeting of the American Chemical Society, New York, N. Y., September, 1963. We are indebted to Reino Hakala (current Address: Univer- sity of Syracuse) who taught in the department and contributed For two years, a grant by Smith, Kline, and-Frenbh Foundation aided ereatlv in freeine fseultv time and eauin~ine laboratories - . - . A. " for new courses. Grants from the E. I. duPont de Nemours & Company m d from the Lubrizol Foundation have also been of assistance. ' From Lord Todd's IUPAC Presidential Address, Chem. Eng. News, Aug. 5, 155 (1963). STROW. L. E., AND BENFEY, 0. T., J. CHEM. EDUC., 35.164 . . (1958). 3 BRTIRER, J. S. "The Process of Education," Hanrrtrd Univer- sity Press, Cambridge, Mass.. 1960, p. 11. a sequence of courses should be based on the major ronrepts that rurrcnrly structure rhemisrry. Thr us1131 ~'hemistrv curricuIum is bawd not so much on conceptual patterns as it is on certain tech- nical skills, exemplified by analytical procedures, or on arbitrary classification schemes which produce such dichotomies as organic versus inorganic. Fortunately, chemists have been able to move a considerable dis- tance toward a unified view of chemical reactions based on principles of electrostatics and mechanics. To what extent can present developments provide a usable basis for the study of chemistry as a science? The first step toward developing a curriculum seems to be to recognize that there is no agreed upon rationale or theory of learning to guide the organization of a sequence of courses. Whatever may be said about chemistry as a science, it is certainly true that develop- ing a chemistry curriculum is fundamentally an empirical procedure. It is, therefore, in a spirit of curricular empiricism that we have been developing a set of chemistry courses. Our approach to instruction in chemistry is consist- ent with a statement by Jerome B r ~ n e r . ~ Students, perforce, have a limited exposure to the materials they are to learn. How can this exposure be made to count in their thinking for the rest of their lives? The dominant view among men who have been engaged in preparing and teaching new curricula is that the answer to this question lies in giving the students an understandine of the fundamental structure of what- events one encounters outside a. classroom . . . . The development in students of an understanding described by Bruner would seem to require a cur- riculum based on a set of major concepts. These we have formulated in the following way: turd and energetic changes. The direction and extent of a. chemical reaction can be related to energy and entropy changes. The rate of a. chemical reaction can be interpreted by a mecha- nism which describes the path of the reaction. Volume 41, Number 3, March 1964 / 133

The Earlham chemistry curriculum

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Page 1: The Earlham chemistry curriculum

Literature Cited (7) MAHAN, B. M., "Elementary Chemical Thermodynamics," W. A. Benjamin Inc., New York, 1963.

(1) KOKES, R. J., DORFMAN, M. K., AND ANDREWS, D. H., (8) NASH, L., "Elements of Thermodynamics," Addison Wesley J. CHEM. EDUC., 39, 16 (1962). Publishing Company, Inc., Reading, Massachusetts,

(2) KOKES, R. J., DORFMAN, M. K., AND MATHIA, T., J. CREM. EDUC., 39, 18, 20, 90, 91, 93 (1962). 1962.

(3) "Editorially Speaking," J. CHEM. EDUC., 38, 333 (1961). (9) HELLER, L. A,, AND HERBER, R. H., "Principles of Chem- (4) STEINER, L. E., J. CHEM. EDUC., 38, 490 (1961). istry," MoGmw-Hill Book Co., New York, 1960. (5) BENT, H. A,, J. CHEM. EDUC., 39, 491 (1962). (10) BROWN, T., "General Chemistry," Charles E. Merrill Books, (6) BURTON, M., J. CFIEM. EDUC., 39,491 (1962). Inc., Columbus, Ohio, 1963.

G. R. Bakker, 0. 1. Benfey, I W. J. Stranon, and 1. E. Strong

Earlham College I The Earlham Chemistry Curriculum Richmond, Indiana

Time was when individuel chemists were broadly aware of developments over the whole of the eoienoe. True, the division of chemistry into organic, inorganic, physical, and anrtlytied ~sectians is of very long standing, but specialists in any one of these used to be an familiar terms with the others. But that time has long passed, thanks mainly to the explosive growth of our science during the past 50 years and the fantastic increase in factual knowledge that bas accompanied it.

The practitioners of the various branches have drawn more and more apart with the passage of time, and only a few yeaxs ago the average organic chemist's knowledge and familiarity with, say, physical chemistry effectively terminated a t the under- graduate level. But within chemistry, just as in science ss a whole, most of the major developments me now occurring in the borderland areas between the traditional divisions, and we can therefore no longer live happily segregated if we me to progress further.

This, of course, poses s real problem in the education of the chemist. The plain truth is that we must re-think the whole matter of training courses and the traditional divisions of the science on which our university and college courses have been based. This is no easy matter I know, but we must all apply ourselves to it and to the related problem of the ancillary subjects of study, for chemistry is also advancing in the borderlands be- tween it and, for example, the biological sciences.'

For the past seven years a t Earlham College we have been puzzling over the problem of developing an ef- fective M resent at ion of chemistrv to undereraduates. Our iniGal plan was described in"1958.~ hi essential feature of the plan for a four-year curriculum was that

Presented as part of the S,ymposium on Reoent Trends in Under- eraduate Curricula before the Division of Chemical Educetion st ;be 145th Meeting of the American Chemical Society, New York, N. Y., September, 1963.

We are indebted to Reino Hakala (current Address: Univer- sity of Syracuse) who taught in the department and contributed

For two years, a grant by Smith, Kline, and-Frenbh Foundation aided ereatlv in freeine fseultv time and eauin~ine laboratories - . - . A. " for new courses. Grants from the E. I. duPont de Nemours & Company m d from the Lubrizol Foundation have also been of assistance. ' From Lord Todd's IUPAC Presidential Address, Chem. Eng.

News, Aug. 5, 155 (1963). STROW. L. E., AND BENFEY, 0. T., J. CHEM. EDUC., 35.164 . .

(1958). 3 BRTIRER, J. S. "The Process of Education," Hanrrtrd Univer-

sity Press, Cambridge, Mass.. 1960, p. 11.

a sequence of courses should be based on the major ronrepts that rurrcnrly structure rhemisrry.

Thr us1131 ~'hemistrv curricuIum is bawd not so much on conceptual patterns as i t is on certain tech- nical skills, exemplified by analytical procedures, or on arbitrary classification schemes which produce such dichotomies as organic versus inorganic. Fortunately, chemists have been able to move a considerable dis- tance toward a unified view of chemical reactions based on principles of electrostatics and mechanics. To what extent can present developments provide a usable basis for the study of chemistry as a science?

The first step toward developing a curriculum seems to be to recognize that there is no agreed upon rationale or theory of learning to guide the organization of a sequence of courses. Whatever may be said about chemistry as a science, it is certainly true that develop- ing a chemistry curriculum is fundamentally an empirical procedure. It is, therefore, in a spirit of curricular empiricism that we have been developing a set of chemistry courses.

Our approach to instruction in chemistry is consist- ent with a statement by Jerome B r ~ n e r . ~

Students, perforce, have a limited exposure to the materials they are to learn. How can this exposure be made to count in their thinking for the rest of their lives? The dominant view among men who have been engaged in preparing and teaching new curricula is that the answer to this question lies in giving the students an understandine of the fundamental structure of what-

events one encounters outside a. classroom . . . .

The development in students of an understanding described by Bruner would seem to require a cur- riculum based on a set of major concepts. These we have formulated in the following way:

turd and energetic changes. The direction and extent of a. chemical reaction can be related

to energy and entropy changes. The rate of a. chemical reaction can be interpreted by a mecha-

nism which describes the path of the reaction.

Volume 41, Number 3, March 1964 / 133

Page 2: The Earlham chemistry curriculum

Concepts, however, have significance only as they serve to impose regularities on diverse empirical data. Each chemistry course, therefore, has been designed to show how certain sets of observations can be interpreted by means of a particular conceptual scheme. Our present curriculum is described in the table.

Term la Term 2 Term 3

Freshmanb Particles of States of The Covalent Chemistry Matter Bond

Sophomore Ions C&mical Knergy

Junior Resonance and Reaction Biochemktw Aromaticity Kinetics and

Mechanism Senior Structure and Seminar Independent

Periodicity Studyd

a Earlham uses the 3-3 system in which a student takes three oourana in earh of t,he t,hxe Terms of the vesr. Thirtv-six ...~... ~~~ -~~ ~~ ~- ~~~~ ~ ~~~ ~ ~ ~

courses. all of which are riven eausl credit."are reauired for graduntion.

b 'The top 20% of those taking freshman chemistry are placed in a separate accelerated sequence of three coumes: mathematics, physics, and chemistry. These students take one chemistry course in their freshman year and then Covalent Band in Term 1 of their sophomore year.

Not required of s, chemistry major, but recommended for students going on to medical school.

d Many students do the oreferable thing of wending a summer . . here in r&earch.

-

Required only of those going on to graduate school.

The courses which make up the curriculum are briefly described as follows:

Particles of Chemistry. Electrostatic and geometrical principles are used to select arrangements of structural units for reactants and products. Classification of substances by bond type is introduced. Laboratory investigations are made of several reactions by means of stoichiometry and calorimetry.

States oj Matter. Solid, liquid, and gas phases and their interconversion are interpreted through kinetic theoiy. The periodicity of the chemical elements is considered in the light of bonding theory and kinetic theory. Further studies of reactions are made using volume, mass, and energy measurements.

The Covalent Bond. The chemistry of compounds formed from elements in the upper right of the periodic table is studied. Particular emphasis is given to the aliphatic compounds of carbon and the nature of functional groups. The laboratory includes prepara- tive work and functional group analysis.

Ions. Ionic compounds are studied with major emphasis placed on equilibria in solution. Labora- tory work includes quantitative analysis applied to student preparations and to equilibrium systems.

Chemical Energy. Chemical change is interpreted through the idea of energy. Enthalpy, free energy, and entropy are developed as a basis for understanding equilibrium systems. Laboratory work is based largely on electrochemical methods for analytical and thermo- dynamic studies. Other instrumental methods are also introduced.

Resonance and Aromaticity. The main emphasis is on the interpretation of reactions of covalently bonded compounds which contain polycentric bonds.

Laboratory work involves preparation and the analysis of products and reaction procedures.

Reaction Kinetics and Mechanisms. The relation between time and change in state is developed as a basis for interpretation of reaction mechanisms. Laboratory work is concerned partly with qualitative organic analysis and partly with Emetic studies.

Structure and Periodicity. Family relationships among the elements and their compounds are dis- cussed, with particular emphasis placed on the stereo- chemistry of transition metal compounds. Laboratory work includes preparative work and also structural and kinetic studies using magnetic, spectrophotometric, and conductometric measurements.

Biochemistry. Some major chemical properties of proteins, carbohydrates, and lipids are studied in the light of ideas about structure and energy. In the laboratory, basic biochemical techniques are studied.

Thermodynamics. Energy, entropy, and statistical mechanics are brought to bear on the interpretation of chemical systems. Major attention is given to the nature of solutions. Laboratory work is concerned with energy measurements, the molecular properties of gases, and with the thermodynamic interpretation of chemical reactions.

Seminar. Reports are prepared and presented by the students on current research literature. A major topic is given intensive study by the entire class. (Hyperconjugation in 1963; xenon compounds in 1964.) An attempt is made to help a student bring together and organize his chemical knowledge in preparation for a comprehensive examination.

Independent Study. The student carries on a re- search study under the direction of a faculty member and prepares a paper on his work in the manner of a journal article.

Textbooks

Unconventional courses such as these lead to prob- lems with conventional testbooks. It is probably obvious that none of the existing texts or manuals entirely suits our purposes. There are, of course, the expected disadvantages to using either a text which does not fit the course content and approach, or to using no text a t all. But there is one important advantage which teachers usually ignore. With a text only partially suitable, or no text at all, both teacher and student are forced to approach the material in a more independent fashion. Both teacher and student are more critical of what they read and more likely to use multiple sources. There is less depend- ence on "what the hook says." In a measure then, poor match between course and text can he used to good advantage.

Another valuable result of a poor match between text and course is that it is only a step from the use of multiple secondary sources to the use of origiual sources. By the time an Earlham chemistry major is a senior, he has learned that the only way to settle an argument or to get the best answer to a problem-outside of actually doing the work in the laboratory-is to look up appropriate information in the original literature.

Use of the chemical literature is, in addition, care- fully fostered in all of the chemistry courses by any

134 / lournol of Chemical Education

Page 3: The Earlham chemistry curriculum

or all of the following methods: assigning research journal articles for reading, urging the students in class and out of class to use the library, devising experiments so that original sources must he sought, requiring term papers on topics not neatly covered in texts or secondary sources. The real nature of a chemist's work is implicit in the research papers written, and students can often learn this for themselves from their reading better than we can articulate it.

Laboratory Work

Student laboratory work is a t the heart of any effective curriculum, hut a good laboratory program is not easy to design. There is a tendency to use a collection of experiments, each of which has a detailed set of instructions that leads to a simple, verifiable result. The aim of a laboratory program should be to get a student involved in scientific inquiry which combines experiment and theory in the solution of a problem. In order to achieve this goal a student must work on problems which are to him genuine, that is, true intellectual challenges. The student must be involved in experimental design. Interpretations should he done by the student in the light of his own data.

We feel that we have only begun to build a laboratory program which satisfies the above criteria. We have found, however, that suitable problems arise most often out of previous classroom or laboratory work. There are other promising leads which we are follow- ing. The method of continuous variations is a powerful tool for studying not only the stoichiometry of a variety of reactions hut also the variety of changes which are associated with and that signify chemical change. With this method, it is possible to display a chemical system in a way that gives a more realistic view than the idealized equations so commonly used as the only presentation.

Energy measurements have proved useful for a variety of kinds of studies. Simple calorimetry can be introduced early with inexpensive thermometers and insulated beakers, while more elaborate devices can be used in advanced work.

Analytical work can he most stimulating when ap- plied, not to artificial unknowns, but to chemical systems to secure data essential to the interpretation of the system. Equilibrium constants, solubility products, and composition studies can all be derived by the student from his own analytical data. These combined with thermochemical data make signifi- cant interpretation possible.

Experimental Curricula

We do not believe that experimental curricula can he compared with traditional ones simply on the basis of relative content coverage. The major question remains whether the student only learns what is presented to him in class and demanded of him in assignments, or whether some doors are opened to hi through which he may go to explore fields far beyond the content of his courses. We are not claim- ing that we do the latter while traditional curricula, do not. However, we do feel that curricula should be judged far more by their success in stimulating inde-

pendent chemical exploration by students and less by the completeness of coverage of topics alone. It is in this area that the Earlham curriculum may have something of general significance to offer. By sub- dividing chemistry into areas with conceptual integ- rity, we believe we are conveying to the students, far more successfully than in our earlier curriculum, a feelmg for the structure of the suhject. And evidence is accumulating that a student is more likely to he stimulated to pursue a subject on his own if he catches on to the stmctural pattern of a discipline. He is stimulated to ask if some of the seemingly logical consequences of the structure are in fact found in nature. Such a "Gestalt" approach to learning is being given increasing attention in discussions of learning theory.

The traditional curriculum is inclined not to he sufficiently open-ended. When a topic has been discussed, there seems little to he asked, to he pursued further. Contemporary science teaching too often remains largely in the medieval pattern. Too often we still tend to teach to supply answers in the form of information, rather than to stimulate the asking of meaningful questions. Presentation of large amounts of information for its own sake tends to sate curiosity rather than to whet it and to direct it into productive channels. On the other hand, a structural approach invites the student to raise questions, to look for evidence, to seek more adequate interpretations.

The aim of chemical systematization must surely be to organize the subject matter through deductive schemes based on a set of postulates. One example of the success of this procedure is given in classical thermodynamics. Ko fact, therefore, should be taught as an isolated fact if it can be related to a funda- mental principle of chemistry. And, if this is once agreed, it seems logical to take the next step, to or- ganize the chemistry curriculum around these funda- mental principles, rather than around superficial resemblances among substances. Such an approach implies that every course becomes a course dealing with a set of physiochemical principles, and that every course contains a considerable amount of descriptive material, the latter being illustrative both of the utility and the limitation of the principles.

Evaluation

There are no agreed upon standards of content for proper chemistry courses; evaluation is therefore difficult. All that we can point to in the way of re- sults are students who have survived our ministra- tions. But such pointing is likely to he unreliable, incomplete, and immodest.

Two groups of students have now graduated with a four-year exposure to our new curriculum. Graduate schools have received them and they have acquired more than an equitable share of special awards and fellowships. With these faint guides the curriculum seems to be workable.

For the faculty the curricular changes have proved stimulating. We have been driven to make more careful study of what we do and why. Whatever else happens, a static unchanging set of courses is no longer possible for us. We see an exciting future for chemistry teachers.

Volume 4 1 , Number 3, March 1964 / 135