Chemical Education Today edited by
NSF Highlights
Susan H. Hixson
Projects Supported by the NSF Division of Undergraduate Education
National Science Foundation Arlington, VA 2230
Curtis T. Sears, Jr.
The Rensselaer Studio General Chemistry Course
Georgia State University Atlanta, GA 30303
Tom Apple and Alan Cutler Department of Chemistry, Rensselaer Polytechnic Institute, Troy, NY 12180
We implemented a studio General Chemistry program as part of a school mandate to replace large lectures in all firstyear courses by small studio classes (maximum of 60 students) that integrate the class, recitation, and laboratory experience. Hallmarks of this approach include focusing on the student as a problem solver and facilitating cooperative learning via group interactions (1). Approximately 900 students take two semesters of General Chemistry: 750 engineering students take a Chemistry of Materials course (2) that adopted this approach in 1996 and the remaining 150 students take General Chemistry for science majors. Five instructors have been involved with the latter course during the last two years. Starting in 1996, these courses meet in two general chemistry suites that we designed to accommodate 60 students each in a studio classroom setting. Each suite is fully equipped for computer-assisted instruction in both the classroom and the adjoining laboratories. The Studio General Chemistry course merges classroom discussion and laboratory work. Indeed, the course material was chosen to complement the laboratory experiments. Classes meet three times a week for a one-hour weekly test and two 150-minute studio sessions. Each session has a one-hour discussion period that is immediately followed by a 50-minute laboratory. During the discussion period, students are seated in 4-person groups (one group per table) that are coached by a faculty member and a TA. Formal lectures are de-emphasized; classroom discussions are driven by posed questions as well as by the post- and pre-lab exercises. By circulating among the tables as coaches, we receive feedback on students’ comprehension and can redirect students’ attention to enhance or reinforce a concept. (A successful class is noisy.) By engaging the students in discussions among themselves and with their coaches, we facilitate their becoming active (and usually willing) participants in the learning process and acquiring critical thinking skills indicative of higher-order cognition (3). After the discussion portion of the class, students move across the hall into the laboratory and continue to work in their 4-person groups. However, they turn in individual pre- and post-lab exercises, which are graded and often are related to the weekly exams. Although the laboratory is constructed with a traditional lab-bench layout, each group station is equipped with a computer and a portable hood (which was designed inhouse [4]). We are still experimenting with post-lab discussions. The problem is that some groups are slower in finishing their tasks, so as in any lab course we rely on meeting with each group during the lab period and asking the ubiquitous questions Why does this happen? and What happens if…? Our laboratory program (two 50-minute labs per week) addresses the sentiment that general chemistry labs are unrelated 462
to lectures (5) and perhaps irrelevant to the overall educational process (6 ). We find that students enjoy and appreciate this merging of classroom and laboratory experiences. Our revelation was observing that most students want to do experimental chemistry. They want to touch, to feel, and yes to smell ongoing “chemistry”. The caveat is that current students need to control or “own” the system that they are working with. We as a department learned this over the last eight years in largely unsatisfactory attempts to implement computer-simulated labs or labs that used a sensor linked to a computer to monitor or control ongoing science. It appears that when the computer becomes the focus of the experimental effort, students lose interest: the experiment is not real. Our challenge then was to design 50-minute labs that involved hands-on activity and remained pedagogically sound. We have been developing new labs and modifying and shortening published lab experiments and demonstrations. Our final labs show a variety and sometimes a combination of pedagogical styles that include (i) traditional or verification labs that however avoid recipes or detailed instructions (except for operating instruments); (ii) discovery and guided-inquiry labs that require the design of the lab procedure; (iii) analytical and detective labs; (iv) synthesis (small-scale) and product characterization labs (mainly organic and polymer materials); and (v) “gee whiz” labs, perhaps adapted from demonstrations (e.g., pulling nylon-6,10 fibers). Two hallmarks of these labs are the pre-lab tutorials and the use of instrumentation. Most of the development effort for this course went into the pre-lab exercises, which serve two purposes. First, the tutorial aspect shows the student how to draw logical conclusions from experimental data (a skill that most students need help with) on a system analogous to that in the lab. For example, the lab on the reactivity of Fe2+/3+ (“minimum/maximum” oxidation states) with colored oxidants and reductants has a pre-lab that discusses related chemistry with Sn2+/4+. Many students need this instruction, in addition to class discussion, in order to “understand” the lab. The second function of the pre-lab is to prepare students to design the actual laboratory procedure in terms of data tabulation and analysis, a necessary step because the actual experimental details are rather terse. Students are expected to transcend merely following instructions: our labs have no blanks to fill in and data tables typically are not supplied. Before doing the classic 5-bottles lab (identifying unlabeled salt solutions through their crossed precipitation reactions), for example, students are “walked through” using a solubility table for setting up the data analysis table for 4 different salt solutions. It has been gratifying to find that many students prepare in advance for the labs with their groups and come prepared with procedural notes.
Journal of Chemical Education • Vol. 76 No. 4 April 1999 • JChemEd.chem.wisc.edu
Chemical Education Today
About one-third of our lab experiments involve the use of instruments: PE 1600 FT infrared (IR) spectrophotometers, scanning UV–vis spectrophotometers, and Gow Mac 350 gas chromatographs (GCs) (one per 3 groups), in addition to the usual grating spectroscopes, digital multimeters, and Spec 20D fixed wavelength spectrophotometers. The first three instruments, although purchased for this lab course, are also found in most undergraduate organic labs. Students respond very favorably to sophisticated instrumentation, although some prompting on our part is often needed to convince the groups that more than one member can actually run the instrument. Even the labs concerned with introducing students to using the IR and GC instrumentation focused on the chemical systems. The first IR lab is concerned with measuring IR stretching “frequencies” as a function of atomic mass and bond order for several organic molecules, whereas the pre-lab deals with calculating similar frequencies and interpreting trends. The first GC lab focuses on the qualitative and quantitative analysis of hydrocarbon mixtures, which the student first works through in the pre-lab tutorial for analogous systems. The scanning UV–vis spectrophotometers are introduced and used in a lab correlating solution colors (Co2+ salts) with wavelength and in discovering the Beer–Lambert law. We feel that it is more appropriate to deal with an absorption spectrum
than to dial in single wavelengths for absorbancy values. We look forward to further publishing our observations on developing the studio classroom (the furniture arrangement matters), on the class pedagogy, and on the development of the 50-minute labs. The entire program will be published by Saunders-Harcourt Brace Publishers in the near future. Acknowledgment This work was partially supported by grants from the National Science Foundation Division of Undergraduate Education: DUE 9555069 (course development) and 9651168 (instrumentation). Literature Cited 1. Wilson, J. M. Phys. Teach. 1994, 32, 518. 2. Wnek, G. E.; Ficalora, P. J. In Materials Chemistry: An Emerging Discipline; Interrante, L. V.; Caspar, L. A.; Ellis, A. B., Eds.; Advances in Chemistry Series No. 245; American Chemical Society: Washington DC, 1995; p. 62. 3. Wnek, G. E.; Ficalora, P. J. Chemtech 1991, (Nov), 664. 4. Sutman, F. X. Chem. Eng. News 1994, 72(Oct 24), 4. 5. Pickering, M. J. Chem. Educ. 1993, 70, 699. 6. Ricci, R. E.; Ditzer, M. A. J. Chem. Educ. 1991, 68, 228.
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