Symposium on the Place of Inorganic Chemistry in the Undergraduate-Curriculum* 0
THE PRESENT PROBLEM IN INORGANIC CHEMISTRY HERBERT C. BROWN and CHARLES L. RULFSl Purdue University, Lafayette, Indiana ~
IT 16 the purpose of the
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present symposium, "The Place of Inorganic Chemistry in the Undergraduate Curriculum," to discuss present deficiencies in current curricula with respect to inorganic chemistry and to examine some of the solutions that have been adopted in an attempt to remedy the situation. Inorganic chemistry is the foundation of the science of chemistry. It may be defined as the chemistry of all of the elements and of all of their compounds, with the exception of some of the compounds of carbon. "Chemistry is the science of substances-their structure, their properties, and their reactions" ( 1 ) . Certainly, few would argue the point that a chemist should be familiar with the chemistry of a representative number of the elements and their compounds. However, a t the present time a large majority of schools have to all practical purposes ceased offering instruction in inorganic chemistry. These schools are graduating "professional chemists" who do not know the properties or reactions of simple common chemicals, who cannot suggest means of preparing or purifying simple inorganic substances, and who do not recognize the hazards involved in certain reactions of common inorganic reagents. These comments are based on contacts with and examinations of graduate students a t several universities. The conclusions may be supported by data obtained in orientation examinations given at Purdue University to entering graduate students2 The results are shocking to one who has not followed the steady depreciation in
* Prermtd at the Symposium o n rhe Plareof Iuorgonie Chcmisrry in the 1Jndwgmduare Curridurn nt the 116th \leering of rhe American Chemical Sociau., .\tlantie Ciry, X r w J e w y , September 20, 1949. Present address: University of Michigan, Ann Arbor, Miohi-
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a These examinations me given to entering graduate students in the fields of amlytical, inorganic, organic, and physical chemistry. It should be emphasized that these examinations are designed primarily to test the students' worbing knowledge of the individual fields and are not designed to test the students' intelThe results of the examination ligence or thinking ability. together with individual interviews are used to guide entering students in electing courses to remedy serious deficiencies.
undergraduate inorganic instruction over the past ten to fifteen years. The most recent such examination with a summary of the replies is given below. Orientation Examination-Inorganic September 14, 1949
Chemistry
(Time allowed: 90 minutes) Right Wrong
8 13
7
56 51 57 M,
1
63
8 13
56 51
8
55 56 50
14
1. Write equations outlining a practical lab* ratmy method for the preparation of the fallowing compounds. (a) Copper acetate (from metallic copper). (b) Hydrogen bromide. (e) Boron fluoride. (d) Phosphine. (e) Silver fluoride (from silver nitrate). 2. Write equations outlining a major industrial process for the manufacture of the following chemicals. (a) Hydrogen. (b) Nitrlc acid. (c) Magnesium. (d) Bromine. (e) Phosphoric acid. 3. Give common oxidation states for the following elements in their compounds. (a) Copper (2 states). (b) Chromium (3 states). (c) Manganese (5 states). (d) Phosphorus (3 states). ( e ) Chlorine (5 states). Compare the behavior of the following substances under the indicated reaction rondit,ions.
(a) Reaction of oxygen with Li, Na, K. (b) Reaction of Zn, Cd, Hg, with sodium
hydroxide solution. (c) Neutralization of &PO,,
HsPOa, and H P O nwith excess NaOH. (d) . . Reaction of AsCla. SbCb. BiClr with excess NaOH. (e) Behavior of NaBrZHnO, MgBrc6H20, .41Bs.6HsO under dehydration conditions. Complete the following reactions. kssume that the experimental conditions are such as to favor the motion indicated, if such a reaction actudly occurs.
438 1 12 7 35 29
63 52 57
JOURNAL OF CHEMICAL EDUCATION
+ -+ + --.+ ++ + + + HNOI (dilute) +H ~ O A
(a) PbsO,
these courses has been reduced, until today many schools have condensed both general chemistry and (c) S CIZ(excess) qualitative analysis into a single one-year course. 29 (d) Co CI, (excess) Moreover, the emphasis has been changed so that little 35 (e) HzS SO2 47 17 I~, f ,) H,S- . -. T, .. -. if any descriptive inorganic chemistry is now taught in 7 57 ( 8 ) H.02 AgNOs these courses. Instead, the first-year course has be24 40 ( h ) BaOl HISOl come a survey course with more emphasis frequently 5 59 (i) CuO NH. being placed on physical, organic, analytical, and indus6 58 ( j ) SO, NHa trial chemistry than is placed on inorganic chemistry. The 64 students who took these tests come from 52 As a result of a recent survey of the content of freshdifferent schools located in 23 states. Sixty per cent of man chemistry courses, Tyree and Knight reached the the students received their undergraduate training in following conclusion ( g ) : A. C. S. accredited Departments of Chemistry. The Less than a handful of departments continue to give the classiaverage scholastic index is higher than 5.0 (5.0 = B), so cal freshman course in descriptive inorganic chemistry. That is t,hat these students must be considerablv above the to say, the bulk of the courses consist of chemical urinciules, such average of the "professional chemists" graduated in as atomic theory, theory of the gaseous, liquid, and miid states, solutions, and chemical equilibria. . . . . Thus, it would appear 1949 from the schools of this country. that instruction in freshman chemistry is tending toward a very Yet but eight shdents of this selected group of 64 elementary study of physical chemical principles, with such d e could suggest a reasonable method of converting copper scriptive material as is necessary to understand these prinoiples. into comer acetate. and onlv one of the 64 recoznized This trend amounts to a gradual, though nonetheless definite, that silver fluoride is soluble in water and could not be divorceof inorganic chemistry from freshman subject matter. precipitated from aqueous solution in a manner analoBefore learning of the earlier survey by Tyree and gous to silver chloride. Other than the electrolysis of Knight, the present authors also carried out a survey in water, which is responsible for an insignificant amount which each department was asked to estimate the fracof the hydrogen produced today, only eight of the 64 tion of time of the general chemistry course which was students could give a major process for the production devoted to instruction in inorganic chemistry. Of the of hydro,xen. Only 13 of the 64 recognized that the 104 schools which replied, fully one-half indicated that major source of nitric acid today is from synthetic one-third or less time of the course was devoted to such ammonia. Even more depressing are the responses to instruction. Indeed, a majority of the large universiquestions 4(b)and 4 ( d ) . Here, even without a knowledge ties indicated that but 10 to 20 per cent of the course of the facts, a student with a working knowledge of the content was devoted t.o descriptive inorganic chemistry. periodic system should have been able to deduce a rea- Yet only a minority of these schools have an "adsonable answer. However, the responses are poorer vanced" course in inorganic chemistry which is required than would have been expected on a pure guess basis. of chemistry majors. Evidently, students today are not only ignorant of the Consider for a moment what such a schedule meanssimple facts of inorganic chemistry, but are not pre- a total of three t o six weeks t o cover the chemistry of pared to use the periodic system for prediction. all of the elements and their compounds! I n discussing Their total lack of feeling for or understanding of the this problem with staff members a t various schools the ' phenomena of inorganic chemistry is illustrated by the authors have learned of courses where the general chemresults obtained in questions 5(b) and 5(i). Only 12 istry schedule permits but one-half a lecture to be destudents either know or could reason that sulfuric acid voted to the chemistry of sulfur and its compounds, a t elevated temperatures might oxidize sulfur to sulfur with the chemistry of phosphorus being completely dioxide; only 5 could reason that copper oxide would omitted. In such courses but one or two lectures are oxidize ammonia to nitrogen and water. devoted to a consideration of the chemistry of all of the The poor response in this examination and in other heavy metals-one lecture to present the chemistry of similar examinations over several years cannot be con- such elements as chromium, manganese, iron, cobalt, sidered t o be the fault of the students. The group is nickel, copper, zinc, and others! The situation with respect to the metals is not remesufficiently large and comes from so many different colleges and universities situated throughout the country died in the qualitative analysis course in those instances that the results must be considered a reflection on the where such a course is still given. In this course the training afforded these students rather than a reflection lectures usually emphasize theoretical topics, such as the law of mass action, solubility product constants, on the students themselves. How have we come t o this dismal situation? At one equilibria, etc., and little or no time is devoted to distime it was general practice to devote two years to cussion of descriptive chemistry. Only in the laborageneral chemistry and qualitative analysis. I n these tory is the student in a position to learn a little of the courses the major emphasis was on descriptive inor- chemistry of aqueous ions, and even here the tendency is ganic chemistry, and the chemistry students received a increasingly toward routine separation procedures and sound foundation of inorganic chemistry on which to spot tests for specific ions with organic reagents which bsse more advanced study. Within recent years two require the exercise by the student of neither knowledge major changes have occurred. The time allotted to nor intelligence for a satisfactory analysis. ~
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(b) S
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AUGUST. 1950
Under these conditions it is not surprising that. for the most part chemistry majors today graduate with an abysmal ignorance of descriptive inorganic chemistry. In connection mith this point, two of the comments accompanying the return of the questionnaire will he of interest. I am delighted to have your kind letter of recent date relative to the present status of inorganic chemistry in college and I must confess that as one who has taught this iylbject in classes averaging about 400 per year, I have noted a very definite trend away from the older type of descriptive inorganic chemistry. My attention was especially called to this while examining two new books which have recently come to my desk. . . . . These two books are indicative of the trend in the elementary course in chemistry. At least one-third of the material in many of these books is given to discussion of organic-chemistry and in some instances comparing favorably with the older type course in this field. Many of these books no longer call themselves inorganic chemistry, but appear under the title "General Chemistry" or "The Srience of Chemistry" or the well-known number of texts under the title of "Principles of Chemistry." Indeed, if one folloms modem texts, the word inorganic chemistry has practically been lost and the first year oi chemistry is usually a hodgepodge of a little bit of information on all subjects (3). I am very much interested in this problem andshall belmking forward to the Atlantic City Symposium. We a t the University of Wisconsin feel keenly the need of more training of our students in descripbive inorganic chemistry. However, when we come to the practical question of giving the students that training, we run into difficulties. First, there is the question of time. There is no place in tbe iour-year curriculum for an additional eoume in inorganic ehemistr.~. We even have to resort to offering qualitative analysis as the laboratory work for the socond semester of general chemistry (4).
It is interesting to note how many departements are unable to find room in their undergraduate curriculum for instruction in inorganic chemistry yet are able to include in the curriculum a required third semester of orpniv (.h~midfry. f r q ~ ~ r n rqlrnlitntiw lg orgianir .tnaIysii. c'nn tlris bc ~hc.rc~ttltoi t h e n~urlird~~nh!llmw ill such departments in the number of staff mith special interests in the two fields, rather than the result of careful decision designed to give the student the best possible training'? I t is unfortunate in this day of extreme specialization t,hat one who retains a broad interest in chemistry is a curiosity to his more specialized colleagues and that the extreme specialists on a staff frequently appear more interested in emphasis of their specialty than in the development of a satisfactory curiiculum designed to give undergraduates a well-rounded training in chemistry. Professor Sorum continues: The content of the field of general chemistry has expanded to the point where one cannot cover the material adequately. In the process of elimination of material to be covered, i t seems 81most inevitable that the principles must be retained. The net result is that more and more descriptive material is being left out o f the course. The new members of our staff are largely young men, trained in theory and inclined to feel that the presentrttion of demiptive and factual material is both unnecessary and boresome (4).
Although there are outstanding exceptions, it appears from these comments and from the other evidence presented that the undergraduate courses in general chem-
istry and qualitative analysis no longer have as their objective the teaching of inorganic chemistry. Moreover, there appears to be no reason to expect a reversal of the trend. On the contrary, it may be anticipated that the time devoted to inorganic chemistry in these introductory courses will continue to decrease. This situation appears to have arisen as the result 01 the operation of three major factors. The vast majority of the students studying general chemistry are not chemistry majors. It appears undesirable to many instructors to attempt to teach students with primary interests in home economics or biology the valences of copper or the reactions of phosphorus. Such students may never have occasion to use such chemical information. As a result there has been emphasis on the teaching of the scientific method and of chemical theories and principles which would be of interest to the majority of nonchemistry majors and would still he of interest and value to the relatively few chemistry majors. Secondly, there has been a tendency to deprecate the value of a knowledge of factual material in favor of an understanding of theoretical material. Such an attitude ignores the fact .that a major function of theory is to permit extrapolation from known facts to unknown information. With no factual information to serve as a basis for extrapolation a knowledge of chemical theory is of little utility. The wider one's knowledge of chemical factual information the more valuable and more useful is a knowledge of chemical theory. As a result of this mistaken attitude we are treated to ths spectacle of graduate students wh:, can glibly discuss such topics as resonance and hyperconjugatiou, hut who are unable to utilize the periodic system or to suggest any reasonable methods for preparing and handling a simple gas such as hydrogen bromide. Finally, there is the factor that the large majority of the instructors in general chemistry courses have their major field of interest in physical chemistry or organic chemistry. Such instructors, without research interest or experience in inorganic chemistry, without the knowledge or background that would enable them to give interest to a discussion of the behavior of the e l e ments and their compounds, resist the introduction of such material in the general chemistry course. They find themselves uncomfortable discussing chemical properties and chemical behavior of substances of which they have no experience other than the tenth-hand descriptions in the textbooks. They are much more a t home with physical and organic chemical topics--subjects with which they have an intimate acquaintance in their own research and reading in the literature. Therefore, the time devoted to these subjects is growing a t the expense of the inorganic material. The trend will probably continue. Unless a department is sufficientlylarge to segregate the chemists and chemical engineers, and possesses a staff with active interests in inorganic chemistry to give a stimulating presentation of the subject, it is probable that inorganic chemistry will soon be practically completely divorced from the first-year course. he question arises as to
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the proper place where instruction in inorganic chemistry may be given. The problem is widely recognized. Unfortunately, few departments have active inorganic divisions. As a result, the few inorganic members of the staff have relatively little voice in bringingaboutasatisfactorysolution. Even the A. C. 8. Committee on Professional Training contributes to the perpetuation of the present unsatisfactory situation. The Committee recommends a one-year course in general, analytical, organic and physical chemistry, plus a year course in advanced work. It has been pointed out that in most schools general chemistry is primarily an introductory course to organic and physical chemistry. It i s not inorganic chemistry. Thus, in effect, the Committee specifies study in analytical, organic, and physical chemistry and students can and do graduate as "professional chemists" without any training or knowledge of the fundaments of inorganic chemistry. Certain comments we have received illustrate the widespread recognition of the problem and the difficulties involved in reaching a solution, I have been giving considerable thought to the problem of the first course in ohemistq and have arrived a t same conclusions which unfortunately do not jibe with the accrediting requirements. For example, it seems to me that it might be possible to give a principle course in the first year with such desoriptive matter as would be helpful hy way of illustration. In the second year, I think it would be just as well to cut down on quantitative analysis to a single semester, using the other SP mester to give inorganic chemistry. This might disturb the analytical chemists but additional work in this field could be taken as an advanced course if desired (6). We are quite interested in learning of your consideration of the auestion because it is one which is of ereat interest to us. ks you may know, we have definitely folloGed the policy that fundamental principles should be taught in the fimt year and a t the same time we also feel quite strongly that most presentday programs are definitely weak in inorganic chemistry. The question of how to meet both these problems is one we consider critical. I am sorry to say that we do not feel we have any really satisfactory solution for the problem as yet (6).
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Certain schools have made some nroeress toward a solution of this critical problem. I n some cases it has been practical to separate the chemistry and chemical engineering majors and to give them a vigorous course which a inorganic chemistry. Needless to say, for a satisfactory solution such a
course should be taught by a staff member with personal experience and special interests in the subject matter. Other schools have incorporated the qualitative analysis course into the general chemistry course and utilize the time thus made available for a sophomore course in inorganic chemistry. One institution, Brown University, has undertaken an intensive revision of the classical undergraduate chemistry courses. Its new program permits a more detailed consideration of inorganic chemistry than is usually possible in the older programs (7). The majority of schools appears to be tending to a course at the junior or senior level, which is required of chemistry majors, with laboratory work involving inorganic preparations. Such a course is then used to satisfy part of the A. C. S. requirement of one year of advanced work. However, it is unfortunate that such courses are frequently labeled "Advanced Inorganic Chemistry" and a major fraction of the time is devoted to such topics as Atomic Structure, Coordination Compounds, etc., with relatively little time devoted to the teaching of descriptive inorganic chemistry. At Purdue, we have introduced for seniors a course termed "Inorganic Chemistry," with two lectures and six hours of laboratory work per week. I n this course the subject matter of inorganic chemistry is presented in a manner similar to that in which the subject matter of organic chemistry is presented in the corresponding organic course. The laboratory work consists of the study of both reactions and preparations and is designed to illustrate the lecture material as well as to give the student personal experience in handling and synthesizing various types of inorganic compounds. Following this course students may elect an advanced lecture course in inorganic chemistry which presents both theory and recent developments in the field, LITER~TURE CITED (1) PAULING,L.,"General Chemistrv," W. H. Freeman, San Frmcisco, 1947. (2) TYREE,S. Y., AND S. B. KNIGKT,J. CHEM.EDUC.,26, 307 1\-"--,. 1 ~ 4 ~ ) (3) GUY,J. S., Private communication. (4) SORUM, C. H.8 Private communication. N., Private communication. (5) (6) ANDERSON, R. C., Private communication. (7) Corns, G. S., L. B. CLAPP:AND R. P. EPPLE, J. CHEM.EDUC., 26, 10 (1949).
