The Subject Matter of a Course in Introductory Physical Chemistry and
I provocative opinion
Over the last twenty years, great changes have taken place in the teaching of physical chemistry and thermodynamics which in some cases may be necessary hut not advantageous. However there are several parameters which have not changed. One is that, in teaching, the subject matter should he based on the students' past experience. This experience should be real experience and not that assumed on the part of the instructor. How many times have we heard the comment, "Oh, they have had that and therefore we don't need to teach it" when in fact the students have not had that whatever that may be. A second consideration is that, in spite of much of the theoretical work that has been done, chemistry is still largely an experimental science. This is especially true in the industrial field. Bond1 has written Chemistry is (or ought to be) fun; chemistry is about smells and colours, about precipitates coming and going, about getting nice ervstals out and even about suoervised banes and flashes. It is not
erperiment. (Italics by author.) By contrast, many of my students have stated that, to them, chemistry is abstract. Senior students have told me that in learning physical chemistry they become very adept at solving and juggling equations but that they really do not know the basics of what they are doing. For a specific case in thermodynamics, what does the concept of the calculation of activities and activity coefficients mean to the students when they do not know the concepts inherent in ideal solutions except as some equation? I believe that an introductory course in physical chemistry should emphasize the properties of hulk systems, consisting of one, two, or possibly three components. This emphasis should include how these properties are affected by the temverature.. pressure. and the com~ositionvariables. . The experimental aspects must be emphasized; as an example, the experimental determination of eauilihrium constants for both homogeneous and heterogineous systems and the extent of reactions when several reactions are taking place simultaneously. Phase equilibria and the colligative properties of binary systems twether with the informat& obtained from thesk in terms of molecular weights, association, or ionization must be included.
44 1 Journal of Chemical Education
Throughout the course the applications of these properties to present-day problems most he brought in to show thereality and importance of physical chemistry to everyday life. The various problems relating to coal, new types of hatteries, materials, and corrosion all lead to interesting discussions. The number of students who do not have and apparently never obtain such information is surprising to me. If thermodynamics is included in the introductory course as it is done in most modern courses, about all that can he expected to he accomplished in the course is the establishment of a firm concept of the first and second laws and how the concepts can he applied to correlate the properties of the bulk systems. The use of thermodynamics to derive the relations is not necessary because theexperimental knowledge comes first and the thermodynamic relations come second. Many of the same ideas most he followed even in an introductory course in thermodynamics. I t must always he emphasized that the behavior of the systems is determined by the laws of nature which have been determined by experiment and not because the laws of thermodynamics require such behavior. The experimental relations should not he deriued from thermodynamics, hut the thermodynamics can be used to correlate the various experimental relations. In an elementary course, it may he advantageous to acquaint the students with some of the compilations of thermodynamic data as suggested hy D a n n h a u s e ~ . ~ But a comprehensive listing can easily overwhelm the students and such a listing may well be postponed to a second course (senior or graduate) in thermodynamics. T o repeat, it is not that the students can not do an assigned task (they hecome very adept in such endeavors) but their ability to do the task is not necessarily a measure of their understanding of the subject matter, their knowledge of chemistry, or their usefulness in the scientific world, particularly beyond academia. Bond, G . C., Chem. in Brit., 10,185 (1974). Dannhauser, Walter, J. CHEM. EDUC., 50,493 (1973).
Scott E. Wood Illinois Institute of Technology Chicago, 60616
