T. 1. Rose ond R. J. Seysel Texas A & M University College Station. 77843
An Upper Level Laboratory Course of Integrated Experiments
We have developed a new, one-year upper level laboratory course to provide a link between traditional lahorator i e devoted to a single area of chemistry and the total involvement of a single narrow research project. Eleven coherent experiments are performed, each of which involves problems that are solved by drawing on information from the various chemistry subdisciplines as well as utilizing the diverse techniques of synthesis, analysis, dynamics, physical -properties, etc. This course reflects the growing trend in chemistry departments around the country to reorganize their laboratory programs in a way which cuts across the usual chemistry subdivisions of organic, physical, inorganic, and analytical chemistry (1-5). The generic name applied to these new programs is the "integrated laboratory." The advantages of this approach have been pointed out in several recent papers in this Journal (1-4). This article reports on our set of integrated experiments as well as some of the logistics associated with the operation of the laboratory. The integrated lahoratory at Texas A & M University is a three credit course which meets in the laboratory 6 hr/wk. Five integrated experiments are done each semester. as well as a special project the second semester. In addition, there are 16 hr of lecture which are compressed into the first 3 weeks of the course. There are two laboratory rooms dedicated to the course. In one room all the synthetic and wet chemical analysis is performed by students using their own glassware and equipment, which is issued to them at the beginning of the course. The other room contains all the major instrumentation, and students go to that particular piece'of equipment necessary to perform the specified experiment. A schedule is drawn up at the beginning of the semester so that each student has reserved the instrument at the proper time in the experiment sequence. This arrangement means that usually no more than three students are involved with the same part of any one experiment. Although a new laboratory manual containing a series of integrated experiments has appeared recently (61, there is still no single textbook which is suitahle for our set of experiments. Several laboratory manuals are available on reserve for student use (6-IZ), but all of the detailed information is distributed on mimeographed handouts. In the past there have been between 18 and 22 students enrolled each semester. These students are usually juniors and have taken a freshman lahoratory course and either two or six credits of organic laboratory. About 15% of the class are junior college transfers or students from other departments. These students have not had unusual problems in adapting to the coursework. Generally the students taking the integrated laboratory are also enrolled in analytical and physical chemistry lectures during the first semester of our course, and physical and inorganic lectures during the second. The lecture portion of the integrated laboratory course is extremely important. Many of the experiments involve theory as well as instrumentation with which the students are not familiar. Furthermore, as mentioned above, since each student is involved with a different experiment, he often cannot be individually instructed before beginning his lahoratory work each period. In addition, experiments
Table 1. Outline of Lectures for the Integrated Labaratorv" Semester I Introduction Ermr A d y s i s Polymer cats1yais S~etmwopy Ligand Field Theory Mass Spectrometry Total hours
Serneak? I1
(1) (5) (2) (2) (3) (2) (1) 16
Introduction (1) Computer (6) (2) Kinetics X-Ray Diffraction (2) Solutions (2) Complex Equilibria (2) Polarograohy (1) ~ d shi"& i 16
=Numbemin parenthesisafter each topic indicate hours of lecture devoted to that subject.
Table 2. Outline of Experiments Performed in the Integrated Laboratory
semester I 1 Cobalt Amine Complexes 2 Preparation and Characterization of Polymers 3 Heterogeneous Catalysis 4 Organometallic Tin Compounds 5 Physical Properties of Gases
6 5 4 4 4
Total
2s
Semester I1 6 Coordination Chemistry of Imn 7 Binary Solutions of Non Electrolytes 8 Complex E urhbria Involving Amino Acids 9 Analysis of%i*ed Crystals 10 Gas Phase Kineties 11 Special Pmjects
4 4
4
4
3
4
Total
B
are sufficiently involved that the students must be given some idea as to how the various parts of each experiment are interrelated. Finally, the type of lahoratory report and data analysis required for the experiments must be explained since they are considerably more demanding and involved than what the students have experienced previously. Lectures are scheduled during the first four laboratory periods in order to cover the material before the students begin the experiments. We have discovered that it is better to concentrate the instruction early in the semester, for as the semester proceeds, the students tend to help one another with the procedure of experiments they have already completed. Table 1 gives an outline of the lecture material and the time allotted to each subiect. In each semester one subject receives particular emphasis. In the first semester the quantitative evaluation of errors is discussed: in the second semester a basic introduction to computing is presented using Fortran and APL. The lectures are designed to fill the particular deficiencies in the students' hackgmund. For example, polymers, catalysis, and X-ray receive special attention since the students generally do not encounter these topics in any of their lecture courses. On the other hand. almost no time is snent on auantitative analysis because the students are co&mently'enrolled in a lecture course in the subject. The lectures devoted to particular experiments are divided about equally between theoretical background and laboratorv techniques. The eleven eGperiments currently in use-are listed in Table 2 along with periods assigned for each one. More detailed descriptions are given in the Appendix. The experiments take on the average of four or five periods. They 'Present address, Howard County Junior College, Big Springs, Texas 79720.
Volume 57, Number 2. February 1974 / 127
are designed t o cover a broad range of techniques using diversified instrumentation in o r d e r t o exhibit a variety of chemical principles. Since the laboratory has replaced the analvtical. nhvsical. inoreanic. . . and instrumental laboratories, the experiments emphasize these areas. Although the students' lecture a n d laboratory experience in organic chemistry is utilized in several of the experiments, this area of chemistry receives less attention. Parts of many of the experiments-have been taken from standard laboratory manuals or published articles. They have been revised, however, t o fit into a larger project so t h a t the principle or technique is not taught merely a s a n exercise b u t rather as the logical method t o obtain the required information. This approach more clearly reflects t h e way problems are approached and solved in both the industrial and university laboratories. The students have no choice of experiments except for the special project. It is felt t h a t t h e students should be introduced to the entire range of topics covered by the experiments. The special project is chosen by the student with the consent of the instructors. Although sometimes entirely new experiments are devised, often the projects are a n extension of one of the experiments they have already done. Projects of this type have often led t o improvements or additions to the basic experiments for the following year. We have found t h a t the new laboratory course offers several advantages over our previous traditional laboratory sequence. Some of these advantages are not necessarily unique t o our version of the integrated concept.
,.
a) The experiments themselves are integrated so that students learn to utilize whatever techniques are necessary to solve their problems without being limited to one area of chemistry. b) The laboratory is a one year course with easily met requirements for any science major reaching the junior level. Thus the laboratory can accommodate students other than chemistry maiors and can he introduced into almost any university curriculum. C) By combining the material which is na
