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New Software Implies New Ways of Learning and Teaching
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John W. Moore
University of Wisconsin-Madison, Madison, WI 53706-1396 |
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This issue is out of print. |
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I have just returned from an ACS National Meeting. As usual I was able to pick up lots of new ideas, but one experience seems especially apropos this issue of JCE: Software. I was waiting for a demonstration of CAChe Scientific software at a booth in the exposition when I overheard the person ahead of me say, "But we don't normally include that in a freshman chemistry course." 'That' was the potential-energy surface for a molecule, presented in stereo 3-D in such a way that one could click a mouse on any point on the surface and the molecule would adopt the conformation corresponding to that potential energy. My immediate response was, No we don't, but we could if we had a tool like this!. What we do as teachers is often determined to a considerable degree by what we can do with the tools currently available. We need to recognize that as those tools change, what we can do (and what we should do) changes as well. This issue provides several tools of just the sort I had in mind at the ACS Exposition. Dick Ramette's Acid-Base is one that I have been using since it was published for IBM/MS-DOS computers in 1989 (JCE: Software 1989, IIB(2) ). Jon Holmes has collaborated with Dick to translate Acid-Base to the Macintosh, and in doing so has transformed it very nicely into a program that is much easier to learn and use because of its graphical user interface. All of the important calculations that are possible regarding acid-base equilibria in aqueous solutions can be easily set up and done by this program. Students (or faculty) can easily determine pH and generate titration curves for a single strong or weak acid or base, or for a mixture of acids and bases. They can view alpha plots that tell what fraction of each substance is conjugate acid and what fraction conjugate base at any pH, and they can obtain suggestions about how to prepare a buffer of any pH and any ionic strength. My teaching has changed because of this software. Instead of asking students to study extensive descriptions and examples of titration-curve calculations, I now ask them to use the program to do the calculations and generate a variety of titration curves. Then they are asked questions that can be answered by examining the curves, not by making several 15-minute calculations. In lecture I demonstrate a titration curve using a computer-interfaced pH probe and relate the demonstration to what they will be doing in the computer room with Acid-Base. In addition to learning about titration curves, students learn that there are computer programs available that can do the grunt work of calculating these things, and that they ought to make use of those programs in future work that involves aqueous solutions of acids and bases...whether that be in chemistry, biochemistry, geochemistry, engineering, or some other discipline. The Acid-Base user interface that Jon Holmes has constructed on the Macintosh encourages exploration of acid-base calculations, and Dick Ramette's pedagogy (JCE: Software 1989, IIB(2), 32-51) encourages students to use the program to explore the theoretical side of questions they may encounter in the laboratory. Given the plethora of computer-based tools that will soon enable all of us to explore the implications of theoretical models, we ought to be encouraging students to learn how to explore on their own as an important component of any chemistry course, including the first one. Programs like the ones in this issue make it possible to do this. The other two programs in this issue also permit and encourage exploration by students. Both involve the atomic-level view of chemical kinetics, though each takes a slightly different approach. Both show the results of collisions of a single atom with a diatomic molecule. Each uses several kinds of graphics, all of which can be juxtaposed in time so that their relations can be inferred easily. Freshman texts often discuss steric effects in reaction mechanisms; one of these programs includes graphically illustrated collisions at the same energy but with different orientations where one results in reaction and the other does not. The other includes a tutorial that allows movement of a point over a contour diagram of a potential energy surface and at the same time shows the positions of three collinear atoms. This could be used as a lecture tool very effectively, and then students could be allowed to experiment on their own, asking their own questions and getting answers from the program. The graphic nature of the Macintosh adds significantly to the program's efficacy as a learning tool. New programs similar to the software in this issue are becoming standard tools of bench chemists in industry, government, and academic research. Those of us who are primarily concerned with instruction and learning ought to be introducing our students to them as early as possible, and providing students with some indication as to how such tools are used by research chemists, biochemists, and many others. As I told my class of freshman students when I returned from Denver, one of the most important things I learned at the ACS National Meeting was the rapidity of development of such tools and the extent to which they will revolutionize research in chemistry and related fields. I promised my students that I would introduce them to more such tools before the semester is over. I hope (and expect) that readers of this journal will do the same. |
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Last Updated: April 26, 2001 Created: December 3, 1996 |
Created by: J. L. Holmes Comments to: jceonline@chem.wisc.edu |
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| © 1997 Division of Chemical Education, Inc., American Chemical Society. All rights reserved. | |