An integrated laboratory lecture sequence in physical-analytical

Brooklyn College of CUNY. Brooklyn, New York 11210. An. Integrated Laboratory-Lecture. Sequence inPhysical-Analytical-. Inorganic Chemistry. The artif...
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Darryl G. Howery

Brooklyn College of CUNY Brooklyn, New York 11210

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An Integrated Laboratory-Lecture Sequence in Physical-AnalyticalInorganic Chemistry

T h e artificially rigid classical structure of chemistry does not adequately reflect the structure of chemistry as practiced today. Analytical, inorganic, organic, and physical chemistry must slowly but surely be reorganized into substructures which will stress greater integration of subject matter and will promote the extension of the boundaries of chemistry. The report of the panel on "The Structure of Chemistry" a t the International Conference on Education in Chemistry [THISJOURNAL, 48, 6 (1971)l contains a thoughtful discussion of the problem and some suggestions for restructuring. Although the desirability of coordinating the undergraduate chemistry program generates much lip service, most chemistry departments are showing little or no desire for an integrated program. We report here a practical plan to decrease the activation energy for interrelating three of the classical subdisciplines. Brooklyn College is a liberal arts college having an enrollment exceeding 30,000. Well over 1000 students each year take the general chemistry course designed for science majors. During recent years, an average of about 100 students have graduated in chemistry. Over half of the chemistry majors are premedical students. Until the introduction of the sequence described in this article, the typical graduate-schoolbound chemistry major took the conventional core composed of two semesters of organic chemistry, one semester of quantitative analysis and two semesters of physical chemistry. Electives include organic qualitative analysis, advanced organic chemistry, two semesters of biochemistry, instrumental analysis, inorganic chemistry, quantum chemistry, mathematical methods of chemistry, and history of chemistry. Only about ten students per year meet ACS certification requirements due primarily to the overabundance of elective courses and to the tendency of most students to avoid laboratory courses. I n order to integrate a major segment of the essential undergraduate courses and to provide better

laboratory training, a three-semester sequence in physieal-analytical-inorganic chemistry has been developed. This integrated sequence represents a major step toward a more meaningful undergraduate program. Outline of Integrated Sequence

After taking a year each of general chemistry, organic chemistry, physics, and calculus, the student as a lower junior takes the first of three laboratorylecture courses. The courses are summarized in the table. The correspondence to conventional courses is over-simplified; in actuality, considerable effort has been made to interweave the fields of physical, analytical, and inorganic chemistry, to avoid some of repetition inherent in the conventional sequence, and to interrelate the theoretical and practical aspects in a more coherent fashion. A suggested order of main lecture topics is as follows (1) PhysieaGAnalytical C h i s t r y Lectures I-theory of gravimetric and volumetric analysis, thermodynamics, solutions of electrolytes, electrochemistry and potentiometry, solutions of nonelectrolytes, phase equilibria, chromatography, kinetic molecular theory. Integrated Three-Semester Sequence

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Physical-Analytiod Chemistry Quantitative analysis, thermoLectures 1 (4) dynamirv Chemical Laboratory Tech- Quantitative analysis, physical niques 1 (8) measurements Phys~cal-AnlyticaChemistry Qumturn Chemistry, spectroscopy, kinetics, instrumental Lectures I1 (4) analysrs Chemical Laboratory Tech- Spectroscopic techniques aad applicztions niques I1 (8) Physical-Inorganic Ohemistry Inorganic Lectures (3) Chemistry Laboratory Tech- Inorganic, instrumental analysis niques h I (8) Lecture and hbbaratory are graded separately. Sequence covers material forma,lly taught in five courses havmg a total of 13 lecture hours and 24 laboratory hours.

Volume 49, Number 5, May 1972

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(2) Physical-Analytical Chemistry Lectures XI-instrument* tion and techniques of spectroscopy, atomic and molecular structure, theories of spectroscopy, kinetics, statistical mechanics. (3) Physical-Inorganic Chemistry Lectures-trsnsition metals, group theory, solid state, polymers, non-aqueous solvents, radioactivity.

The laboratory sequence stresses research techniques and instrumentation. Little effort is made in the laboratory merely to illustrate theoretical topics covered in lecture; instead, an understanding of and the ability to use the major experimental methods and the critical evaluation of results acquired in the laboratory are stressed. Major areas for laboratory work include (1) Chemical Laboratory Techniques I-calculational techniques, gravimetric and volumetric analysis, calorimetry, determination of physical properties. (2) Chemical Laboratmy Techniques XI-gadiquid chromatography, electrical measurements, potentiometry, conductimetry, spectroscopy (uv-visible, speetrofluorimetry, infrared, proton magnetic resonance) project. (3) Chemical Laboratory Techniques III-polarography, preparation and characterization of inorganic coordination compound, non-aqueous titrations, radiochemical analysis, project.

The third laboratory course can be more open-ended, experiments being chosen in part according to the backgrounds and the desires of the students. Reports in journal manuscript format are required for most experiments. For the two to three week research project an oral presentation of results to the class is recommended. Some Comments

The sequence deliberately emphasizes analytical chemistry and the intelligent use of instruments. We hope to reverse a trend a t the upper undergraduate level which emphasizes theoretical material to the exclusion of experimental work. A marriage of the abstract and practical is realizable within the framework of the proposed sequence. Students taking only the first two laboratory courses should be more adequately prepared for graduate research than those who take the standard sequence of one semester of analytical and two semesters of physical chemistry laboratory. Students taking the entire integrated sequence plus

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organic qualitative analysis should be well-trained experimentahts meeting all the requirements for ACS certification. Planning and putting into operation an integrated sequence is a valuable educational experience for a chemistry staff. Professors with diierent backgrounds find out (in most cases for the first time) what is done in other subdisciplines. If our experience is indicative, resistance of the staff to course integration will be rather widespread and surprisingly strong. The Brooklyn College sequence was planned mainly through the efforts of two physical chemists, two inorganic chemists, two analytical chemists and an organic chemist. The program presented here is definitely a compromise; without a doubt a department's entire offerings should be tightly coordinated (which is easier said than done especially in departments having large staffs). A relatively long range but realizable program could entail three steps: (1)integration of the physicalanalytical-inorganic offerings, and (2) integration of the organic-biochemistry courses, followed by (3) overall integration. Regardless of the exact procedure adopted, the advanced courses should be based upon the framework set in general chemistry. Brooklyn College is currently offering both the conventional and the integrated sequence. Evaluation of the new sequence will require several years. We do feel that team teaching works quite well in the laboratory but that each lecture course should be given if possible by one professor who has the knowledge and desire to integrate the material. The main objection of the students is the large number of laboratory reports required, a valid objection which can be alleviated somewhat by theuse of more oral reports. Acknowledgmenl

The valued counsel of Professors Harmon Finston, Vojtech Fried, George Gibson, Joseph Glickstein, Takanobu Ishida, Gary Mennitt, Robert Odum, Orest Popovych, and Evan Williams is gratefully acknowledged.