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A Review of Curricular Changes in the General Chemistry Course during the Twentieth Century Baird W. Lloyd Emory and Henry College. Emory VA24327 Every time a curriculum revision process begins, questions arise: 'What is the ~ u m s e ? "'Whv . now?". "Isn't this what we did the last time?: The'reviGon of t'he general chemistrv Droeram, undertaken bv the Task Force on the General khem&try'~urriculumofthe American Chemical Society, has generated the same question set. This paper seeks to answer the questions by describing the evolution of the general chemistry course in terms of its content and the forces that have directed the content revisions. The discussion is limited to the class (or lecture) portion of the course because that is how the literature has recorded the changes, even thoueh most teachers would agree that laboratory is an essential part of introductory chemistry In this century the curricdum has undergone two radical changes, one aborted effort, and the current process. The first chanee. which beean earlv in the centurv. occurred because-the nature OFthe science of chemistry underwent a fundamental change. The second revision was a response to the changing nature of American social concerns and the needs of the students who took the course. All of these factors-the science, society, and the student, in differing degrees-have continued to influence the general chemistry curriculum during the last 30 years even though no major change has taken place. Two aspects that have remained invariant are the general goals for student learning in the course and the extended time it has taken for any significant change to be fully implemented. Cornog and Colhen rl~attributedthe slownew tuthe fact that "undignified haste is not to be numbered among the sins of teachers of elementary chemistry." Setting Goals for the General Chemistry Course Throu~houtall the criticisms, sumestions, evaluations and changes expressed in t h e h u a r e d s of articles reviewed for this paper, it was interesting to find a small set %orfor the General c h e i i s t r y course that of common has persisted from the beginning. Most recently the set has been summarized a s having students learn "what chemists do and how they do it" ( 2 4 ) . Areport of the Committee of ~- Chemical Education for the American Chemical Society in 1924 (5)included the goals of training students in "keen observation" and "exact reasonine". The eoals of developing skills in the various processes of scientific investigation were repeated, usually in a more elaborate form, in 1930 (61,1941 (71,1954 (81,1974 (31, and 1991 (9). The other common goals include ~
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(1) Presenting a comprehensive view of chemistry and its sig-
nificance to civilization (4-6, 9). (2) Developing in students an appreciation of the spirit of science and the scientific method (2, 3, 68, 10). (3) Developing in students critical judgment, self-confidence, a willingness ta suspend judgment, and the ability to think for him or herself (3, 4, 6, 9).
(4)
Nurturing a sustained interest in chemistry (4, 6, 7, 11).
In addition to this common set, various other goals have been added during the century, mostly in response to the channna nature of students' needs. For example, the develofmeit of goals concerning ethics and values appeared in the 1970's (2) when students were calling for "relevance" in all their courses. Goals stressing problem-solving skills appeared in the 1980's, in response to criticism about the thinking skills of students. These goals have functioned as the criteria by which content has been selected, instructional strateeies developed. and evaluation ~rocedures prepared. he interpretation of these criteria has cteated the differences existing in the various curricular revision processes. Significantly, the set of commonly agreed upon ~ o a l has s never included a single, body of knowl- . specific edge that should compose the general chemistry course content, yet this aspect of the curriculum planning process has received the most attention each time a change has been proposed. The Evolving Science and The First Curriculum Change Durine the first ouarter of the twentieth centurv. the content Gf the intro&ctory courses in chemistry, wcether taueht in hieh school or college. - . was descri~tiveinorzanic chemistry. Topics were organized by chemical element, covering their reparation, compounds, reactions, and industriaiapplsatio.ns. No general principles or themes unified orexplmned these bundles of facts. Texts of the penod presented each topic as a separate chapter, yielding book that contained an average of 600 pages divided into 30-50 chapters (12, 13). Some courses included a discussion of hydrocarbons and their derivatives as part of the chemistry of carbon (14).The only major controversy during these early years was whether to put qualitative analysis in the General Chemistry course or teach it as a separate course in the second year. This issue became so controversial that Elving labeled qualitative analysis the "stormy petrel* of the chemistry curriculum (15). The changing nature of chemistry as a science precipitated the first change, which began after the First World War and continued into the 1950's (16). The description of the nuclear atom by Rutherford, the discovery of the neutron, the Debye-Huckel principle of strong electrolytes, and the Bronsted-Lowry acid-base principle gave new meanine to the properties of atoms and isotopes. the concepts ofYsalts aAd hydrolysis, and the signi&a&e of the periodic table. Scientists now had a theoretical basis on which to organize, interpret, and explain atomic structure and ionic valence as well as to find unifvine ~ r i n c i ~ l for es what had been so long a series of isolated &ts abcmt the chemistry of the elements. In 1927, the Committee of Chemical Education for the American Chemical Society (17) called for a change in in-
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tmductory wllege chemistry wurses to reduce the overlap between them and high school courses. More importantly, the new courses were to teach the principles and theory being used by research scientists. The recommended syllabus, based upon a student having had high school chemistry, was to cover (1) the structure of matter, including the fundamental laws, an experimental treatment of gases, and properties of atoms, molecules and ions; (2) the classification of elements in terms of atomic weight, atomic number, and periadic pmperties; (3) the electronic conception of ionization, factors affecting equilibrium, and the properties of adds, bases, and salts; (4)the chemistry of metals and of the phosphorus, sulfur, earbon, and halogen groups; and (5) qualitative analysis, in terms of the relevant compounds, tests, and reactions. Textbooks of the decade changed in line with the 1927 recommendations. In 1937,Dunbar, in a survey of 12 general chemistry textbooks (181,found that 12.5% of a text was, on the averaee. devoted to oreanic chemistnr. The texts that emphasized theory, inorg&ic, and physi&l chemistry had the least amount of organic chemistry. Courses of the New Curriculum Change was slow in wming. Selwood in 1939 (19)and Sisler in 1948 (20)were still nleading for teachers to use modem theoretical principles as the-organizing basis of the course because descriptive chemistry was "dull". A study published in 1949 (16)reporting on general chemistry courses in 60 departments having programs appmved by the American Chemical Society described the majority of the courses as "tending towards a very elementary study of physical-chemical principles with such descriptive material as is necessary to understand the principles". Another survey of 65 institutions in 1954(21)found that ody 15% of class time was spent on metals, nonmetals, and their compounds. Organic chemistry occupied 3.5% of the time. Twenty-three of the institutions (35%)did not include qualitative analysis in the course. By the end of the 1950's the general chemistry wurse in most colleges followed a of teaching general principles. Dcscrlptive inorgan~cchemistry was introduced only io illustrate the prinuples, drawing examples fmm both inorganic and organic substances. The course at Harvey Mudd College (22)was based upon laboratory and classrwm experiments that were not simply a demonstration of known ideas. Atomic and molecular structure were covered in the first semester. Chemical equilibrium, both oualitative and ouantitative asnects. formed the content of [he second seme'ster. At ~ a r l h a mcb1lege (231,the course in the first term focused on atoms, atomic structure, reactivity, and reaction mechanisms, with covalent chemical bonding in the second term. Ionic bonding was covered in a separate second year course. Pauling's College Chemistry, a popular text of the period (241,began with the nature of chemistry and the properties of matter. Eleven of the remaining 31 chanters contained the chemistry of the common elements. ~ e i e r aprinciples, l includine oreanic. biochemistrv. and nuclear chemistnr anpeared aTso.he k m b e r of pages of this text, and othirs bf the decade, remained the same a s before, but the size of the books increased from 5 x 8 in. to 6 x 9.5in., thus allowine more words oer . oaee. . - The information wvering.. ..Zenera1 principles became an addition, rather than a replactment. for the descrintive chemistw. This nattcrn of addina new material without significantiy red;cing the old has continued to the present day. I t is a good indicator of the ever-increasing amount of material that students have been expeeted to master in the wurse.
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Along with the changing curriculum came the first suggestions for separate types and levels of general chemistry courses. Wakeham (25)proposed a common course emphasizing descriptive chemistry for two-thirds of the year, followed by a separation of the advanced students to study theory. Ashford (26)suggested offering a separate course for nonmajors so that the training of specialists could go on separately fmm that of others who studied chemistry for other purposes. In 1956,Vandenyn reported the results of a survey of 127 institutions (27)that showed 71.7% of the group offered at least two different sections of general chemistrv. Students were segregated on the basis of ability, previousexperience, and interest. The coverage of some of these courses was less technical and bmader than those used for chemistry majors. The Evolving Student and the Second Curriculum Change Fifty years of the century bad passed before the first revision was complete. Yet before this change was f i d y established, the second major change began. Society was becoming more technologically advanced as a result of scientific efforts during the Second World War. Many students were taking chemistry in preparation for professional careers other than chemical research (28).Aiter the war ended, the number and maturity of entering students increased as veterans joined the college ranks (29).New high school courses, like CBA, CHEM, PSSC, and high school Calculus provided students enterine colleee with more soplusticatc?dscientific knowledge and'matheiatiral skills (30,. The result was a change to a aeneral chemistry course that emphasized the ab'tract, mathematical aspects of physical chemistry. A survey concerning the course content, reported for 105 'institutions in 1961 (31),rated phase rule, biochemistry, free enerm thermodynamics, and entropy as r e l a t i v e l ~ u ~ m ~ o n a ~ ~ c obv n cthe e ~ mats -ionty- of the schools. The most lmponant concepts mcluded the periodic system, ionization of acids, conckration of solutions, and atomic structure. In a follow-up study done ten years later (321,having essentially the same list of concepts from which to choose, the items that increased in imnortance for the maioritv " " of the resnondents were all theoretical: entropy, free energy, quantum numbers, and thermodvnamics. All ofthe items that decreased in imwrtance were from the arca ofdescriptive inorganic chemistry. Bv 1976 133, the second curricular chanec was nearlv comSeventy-three percent of 500 institutions surveyed in 1962 (34)had changed both their sequence and content of courses for the major. Courses, such a s ones taught at The Johns Honkins Universitv (30).Brown Universitv " ( .35) ... and ~ o s t o hUniversity (36emphasized thermodynamics, nhvsical chemical orooerties of matter. and theoretical koedels. Fuller (37)reported the existence of 82 multidisciplinary first-year courses a t 64 institutions. The most common combination was chemistry and physics. A n example of this interdisciplinary approach was the contents of the first term at Beloit College (381,which included principles of work, enerm the atomic nature of matter, mass relationships, el&ricity, electrochemistry, and free energy. Magnetism, the Bohr atom, electron configuration, and the periodic table were covered during thesecond term. In 1962,well-prepared students at Amherst College (39)were allowed to begin with chemical thermodynamics in class and quantitative analysis in the laboratory. Lebanon Valley College (40)and Haverford College (41)allowed their highly ranked students to go directly into organic chemistry. Popular texts reflected the nature of the curriculum changes. The first edition of Chemistry by Sienko and
Plane (42), published in 1957, stressed general principles interwoven with descriptive material. By 1966 these authors had two versions of this text, one similar to the original, and one in which the approach to each topic was more detailed and mathematical. This new version also contained thermodvnamics. Chemical thermodvnamics. including enthalpy, entropy, and free energy concepts, apoeared earlv (Chaoter Five) in Masterton and Slowinski's krst edition of chemical ~ & c i ~ l e(43). s In this text, also, descriotive chemistrv was orwnized around the types .. of chemical reactions: acid-base, redox, and complex ion formation. Gone were chaoters on individual chemical elements and their compodds. Nebergall and Schmidt produced two types of general chemistry texts (441, which differed primarily in that one of the texts arranged the chemistrr of metals into chapters on qualitative analysis. Both texts included much mire descriptive chemistry than contained in other popular books because the authors believed that such description was an important part of the first-year course. As the books underwent revision, more ohvsical chemical tooics were included in olace of some of " the descriptive details. Jay Young, in the first P~)wcatiue Oninron column oubhshed in the Journal of Chemical Education (451, suggested that the time had come when there would never again be only one good way to structure the curriculum in chemistry. He believed that the classical cutting of content into pieces called inorganic, organic, analytical, and physical was no longer viable.
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The Last Thirty Years: a Time of Ferment
There have been no further major changes in the general chemistry course. As technological advances in instrumentation and computers have allowed scientists from a variety of fields to investigate and interpret more complex systems, the general chemistry course has grown gradually more complex, using more mathematical abstractions to i n t r o d u ~ e ' ~ r i n c i ~ lThe e s . amount of material students have been asked to learn has grown dramaticully. Unfortunately, the characteristics ofstudents entering chemistry courses have changed also. Students of the 1950's, best known for being selfmotivated, goal-directed, and willing to delay gratification (461, evolved during the 1960's into sociallv conscious oersons who reearded chemistw as an "ivory"tower enteiPrise in which;hey did not see themselves" (47). Better prepared students were choosing premedical tracks rather than ones that would lead to a career in chemistry (48). In the 1970's, students sought "relevance" and education as a means to economic improvement rather than as a source of intellectual simulation (46, 49). Astudy ofwashington State University students published in 1976 (50) showed a 10%decline in science knowledge and a 16% drop in basic math skills during the first six vears of the decade. SAT scores, which had risen steadily from the late 1950's to 1963; declined through the 1970's (51). A 10-point drop in average scores in 1975 was the largest ever reported. The Washington State University study (50) showed that, during this period of declining test scores, there was not a corresponding drop in high school grade point averages. Also, public interest in science, which was high at the beginning of the 19608, declined in the 1970s (51).Lippincott cited increased complexity in science coupled with a society that was moving from intellectualism towards a pleasure-seeking lifestyle as causes for the decreased interest and skill in chemistry (52). There was no shortam of criticism of the curriculum once the change in student skill levels and attitudes became apoarent. Davenport, in 1968 (53), suggested the course placed too much emphasis on math, uoienough on chemistry itself. In doing so, the course did not suit the "bottom
90%" of entering students. Eight years later (54) he complained that students used so much theory that they were out of touch with reality. This complaint was an echo of Kieffer's criticism that students with so much theory could "locate electrons in a n orbital but not predict what would h a o ~ e nif two chemicals were mixed" (55).Nash felt that th; emphasis on mathematics in the General Chemistry course prevented the students from understanding the qualitative nature of systems and chemical change (33). Skill in mathematics was not necessarily evidence of understanding of the important r e l a t i o n s ~ ~ of~the s system. Pauling believed that the addition ofmolecular orbital theory to the general chemistry wurse simply sewed to confuse students (56). Many of the curricular reforms attempted in the 1970's were in the form of special types of courses (57-601, including the institution of preparatory courses for underprepared students and specialized courses for nonscience majors. An unsuccessful attemot to restore descriotive inoreanic chemistry as a major c ~ & ~ o u eof n tthe geieral chegstry course occurred during the 1980's. Bodner and Herron (61) supported the creation of a balanced treatment of fact and theory, suggesting that the descriptive material could be used to illustrate principles or be used as a starting point from which to introduce principles. They noted that teachers of the period were graduates of the "elementary physical chemistry school" of general chemistry and, therefore, might need help in putting together such a course. In addition to the suooort of the teachers, MCAT and DCAT ~ ~ ~would need to be changed exams, and s t i d a r d exams to support this new course content. Unfortunately, this support did not materialize. Gorman (62) attributed the failure of this curricular change to the reluctance of teachers who might have perceived the change a s an unscientific regression for chemistry. We &e now two years into the 19908, the last decade of the century. The American Chemical Society has once again appointed a committee to study and revise the general chemistm course. We hear once again - echoes of earlier days... Glenn Cmby, in saying the course should be "dynamited" (631,reminds us of Stafford's suggestion in 1930 (64)that the course should be Yruthlessly scrapped". .Alice Cunningbarn (65)suggests, as did the Committee on that the course should Chemical Education in 1927 (17), stress principles that are related ta everyday problems. Four of the five chemical concepts considered most important hy researchers in the field (66):formulas, mole crmcept, properties ofmatter, acid-base andionic equilibria concepts, were also on the list suggested in 1927 (17).
The list could go on; but, as Spencer said (671, "nothing much has come from all the talk of the past thirty years". The most obvious example of this resistance to change apDears in the o o ~ u l atextbooks r used today in general chemistry What began as a compendium of faits aTbout chemical elements has become a n encyclopedia of principles and their applications. The page size has doubled to 8 x 10 inches, with an average of 1000 pages, weighing a n average of 6 lb! From the simple suggestion that linear relationships should be used to give students confidence in the use of mathematics to exoress laws and orincioles (68) . . has come hundreds of math broblems that ieave students believine the orocess of solvine word oroblems is the same as learnLg wgat chemistry t h l probl~msrepresent. ~~~
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The Questions Answered In 90 years the main goal of the general chemistry course with respect to content has not changed: to introduce students to the most important, fundamental laws, principles, theories, and applications of chemistry. Nor have changed
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the goals of developing in students the ability and the spi& to investiga~ch&ical systems in a rational, systematic way. The specific obiectives needed to reach these goals have changed and, apparently, need to change again. The courses, as currently structured, are not attracting talented students nor are thev orovidine the ex~eriences needed to produce students d o ' h a v e a f bfouidation of basic skills needed to think and act as a scientist. Perhaps, now, it is time to look at the other "invariant": the reluctance of teachers of general chemistrv to im~lement change. The two, earlier curricular changes were easilv acce~tablebecause both involved u ~ d a t i n eand UDgrading coirse content to reflect new knowledge in the shence of chemistry. Now, however, the curricular change must be a response to changes in the way students learn chemistrv, reauirine changes in methods of instruction and eva1;atio;. ~ h e - w ateachers ~ interpret course goals, lay out the learning objectives for students, evaluate their progress, and imbue the students with a sense of wonder and excitement for learning chemistry, affects the outcomes of the course for stud&. Many suggestions have appeared in articles written about the general chemistry course during the past four years (63, 65, 67-74). These critically important aspects of the changing general chemistry curriculum will be reviewed in a subsequent article.
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