Chemical Education Today
NSF Highlights Projects Supported by the NSF Division of Undergraduate Education
Internet-Based Prelaboratory Tutorials and Computer-Based Probes in General Chemistry by Brian P. Koehler and Jessica N. Orvis
Prior to the Fall of 2001, general chemistry labs at Georgia Southern University (GSU) consisted of traditional workbook verification-style laboratory experiments. A strong desire to upgrade the general chemistry laboratory program through greater use of more modern laboratory techniques led to a proposal to NSF-DUE that was subsequently funded to purchase computers and interfaced analytical probes for the general chemistry laboratory program. Included in the project was a complete restructuring of many of the traditional laboratory experiments to utilize the new equipment. There are two primary goals for the project. The first is to introduce students to instrumentation used in modern science labs with the aim of better training them in the job skills required in the workforce today (1). The second is to demonstrate real-world applications of skills learned in the laboratory curriculum in order to generate student interest in the study of chemistry (2). An additional aspect of the project is the development of Internet-based prelaboratory tutorials aimed at familiarizing students with the concepts, procedures, and technical skills associated with the experiments. These tutorials provide students with better preparation for the experiments and ease the adaptation of the new technology into the laboratory program.1 Advantages of Computer Use Initial new laboratory experiments focused on use of the new analytical interfaced probes. In addition to designing labs that use the interfaced probes, molecular modeling and spreadsheet software were also incorporated. The benefits of computers and computer-based probes in the laboratory have been well documented (3–5). Particularly beneficial to the general chemistry program has been the savings in laboratory time. The time saved has translated into new experimental procedures that expand on conceptual understanding and explore related applications. For example, the old freezing point depression lab consisted of drawing two freezing point curves by hand: one for distilled water and one for a dissolved unknown. The interfaced temperature probes save time in data collection, which has enabled students to complete not only the two curves from the old lab, but also two extra curves that explore the relationship between molecular formula and concentration of ions in solution. Time saved from data collection also allows for expanded studies, including conceptual questions that explore the nature of deicing agents. Other experiments have been expanded to address issues of interest to our students, who are primarily from rural regions; this includes experiments that relate solution con606
ductivity to crop yield and vapor pressure to weather. Even without interfaced probes, several labs have benefitted from the use of spreadsheets and molecular modeling software that have been enabled by having the computers. For example, an experiment that explores the periodic trends of the elements now has an added section using HyperChem Lite modeling software2 to study structural patterns in elements from the same group and trends across a period. Additionally, Web access in the laboratory has allowed students to access other information needed during the laboratory, such as current weather and atmospheric conditions, definition of terms, and other standard reference data. Internet Prelabs In order to ease the transition to the new laboratory experiments utilizing the computers and probes, new prelaboratory activities were developed. Previously, prelab activities typically consisted of a partially filled-in table that was identical to that found in the experiment itself; the student practiced the calculations by completing the table. These activities had only limited educational value and did nothing to prepare students to use the new computers or the attached analytical probes. We decided to develop Webbased prelaboratory tutorials that would use the visual and interactive nature of the Internet to familiarize students with the new lab equipment and give them a clearer picture of what was expected in lab. The new tutorials show the setup and use of the laboratory equipment, demonstrate the skills and techniques that will be needed, and emphasize the concepts of the experiment. The use of photographs in the new prelaboratory tutorials was instrumental in helping students adapt to the new computer-based equipment. All the new computer-based experiments have prelab tutorials that begin with a photo that shows the initial set-up of the equipment. When students recognize the experimental setup, they do not have the anxiety associated with using previously unseen equipment, and they can begin with a greater degree of confidence. Photographs with interactive prompts also familiarize the students with the proper use of the probes. For example, the working parts of the epoxy-encased conductivity probes are not clearly obvious to the students. In the tutorial, students are shown two photographs of a conductivity probe in solution. Although the tip of the probe is touching the solution in both pictures, one shows the probe fully submerged and the other has the hole leading to the electrodes only half submerged. Students are required to click on the photo showing the proper use of the probe before being allowed to continue.
Journal of Chemical Education • Vol. 80 No. 6 June 2003 • JChemEd.chem.wisc.edu
Chemical Education Today edited by
Susan H. Hixson National Science Foundation Arlington, VA 22230
Richard F. Jones Sinclair Community College Dayton, OH 45402-1460
Those who click on the wrong photograph receive a prompted message explaining that the tip of the probe is not the functioning part and emphasizing the importance of completely submersing the probe, as shown in the other photograph. This use of photographs brings the important techniques in the experiment into clear, memorable focus. Such images have been invaluable not only in preparing students to use the computer-based probes, but also in helping them identify other unfamiliar equipment named in the procedure (such as a “Büchner” funnel, “Dumas” bulbs, etc.). This has been very important for those students with limited prior chemistry experience. The use of photographs has also brought more focus on some of the finer or critical details of the experiment in ways that the students can notice and remember. For example, one lab tutorial has a photograph that shows using a conductivity probe to make measurements. Next to it is a photograph that shows the beaker and probe tipped over, with the beaker contents spilled on the counter. The caption warns students that because the cord connecting the probe is heavy, their sample can easily spill if the probe is not secured while it is in the beaker. Students can also learn some other fine points in good lab technique, such as using a stirring rod when decanting, by looking at a person performing the technique. Even if not specifically described in the procedure, students sometimes remember and use the techniques because they emulate the methods they have seen when doing the prelab tutorial. Describing a procedure with both photographs and text has given students a clearer picture of what they will be doing in the lab in an easily remembered format. The presence of computers in the lab has also allowed the online tutorials to act as a handy reference for students during the experiment. Without such additional guidance, beginning students are prone to procedural errors that result in repetition of the experiment, loss of time, and high frustration levels. Internet access in the laboratory allows students to view the prelab Web site during the experiment and use the material there as a guide during the procedure. The tutorials give particular emphasis to areas in the experiment where there are potential problems. In addition, to help avoid student injury, safety-related issues are prominently featured. The use of these prelaboratory tutorials allows students to arrive at lab more confident in their understanding and more prepared to perform the experiments, thus making the laboratory experience more positive for everyone involved. At the end of each prelab tutorial is a quiz that students must complete before the beginning of the laboratory period. While these quizzes often include sample data for students to practice the mathematics involved in the proce-
When the edit box opens, this time type “1” for 1 drop of NaCl added. Note: When measuring the conductivity, be sure to hold on to your solution! The probe and its cords are heavy and will tend to pull the beaker over to one side…
so you could end up like this! And yes, you will have to start over if your sample looks like this. Figure 1. Example screen from Internet Prelab Tutorial on electrolytes and conductivity.
dure, they also ask questions about important concepts, procedures, and safety issues. Furthermore, because of the ease of including images on the Internet, some of the quizzes include photographs of possible experimental results, which students are then asked to interpret. Visual interpretation of sample lab results was not feasible with earlier paper-based quizzes, due to the low copy-quality of the paper-based prelab quizzes in the lab manual. Now students complete the quizzes online and then print the quiz with their answers before coming into the lab. Requiring students to answer the quizzes online before printing has the additional benefit of ending last minute copying of quizzes in the hallway. Conclusions Our new system has many advantages: •
There is more time in the laboratory for additional data analysis and expanded studies
•
Prelab tutorials replace a lengthy prelab lecture
•
The transition from workbook-style labs to computerbased labs has been much easier
•
Students come to lab more confident and ready to begin work
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Chemical Education Today
NSF Highlights The new laboratory experiments and tutorials required significant time demands on only two faculty. The prelab Web pages were built using simple design software included in the Netscape Web browser software3 and thus required little training. Of course considerable time is needed to develop new labs and Internet-based tutorials to accompany them. This has mandated that these changes occur gradually, which has greatly eased the transition into the new laboratory program for faculty and students alike. Statistical data are being collected on student and faculty perceptions of the effectiveness of the new lab experiments and prelaboratory tutorials. Acknowledgments Partial funding of this project was obtained from the National Science Foundation’s Division of Undergraduate Education, Course Curriculum and Laboratory Improvement Program, Grant No. DUE-0088586. Matching funds were generously provided by Georgia Southern University. Particular thanks are extended to Jim Lobue and Jeffrey Orvis. Notes 1. View the GSU Chemistry Prelab Tutorials online at http:// www2.gasou.edu/chemdept/prelabs/ (accessed Apr 2003).
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2. We used HyperChem Lite version 1.2, which is available from HyperCube, Inc. Scientific Software, 1115 NW 4th Street, Gainesville, FL 32601; http://www.hyper.com (accessed Apr 2003). 3. Netscape Composer Web design software is part of the Netscape Communicator Package. During the course of this project several upgrades have been released and were used: versions 4.75, 6.01, and 7.01. The software is available free from Netscape Communications Corporation, http://www.netscape.com (accessed Apr 2003).
Literature Cited 1. Durick, M. A. J. Chem. Educ. 2001, 78, 574–575. 2. Beiron, J. F.; McCarthy, P. J.; Kermis, T. W. J. Chem. Educ. 1996, 73, 1021–1023. 3. Deschri, P.; Jones, L; Heikkinen, H. J. Res. Sci. Teach. 1997, 34, 891–904. 4. Donovan, W. J.; Nakhleh, M. B. J. Chem. Educ. 2001, 78, 975–980. 5. Jones, M. B. J. Chem. Educ. 2001, 78, 867–868.
Brian P. Koehler and Jessica N. Orvis are in the Department of Chemistry, Box 8064, Georgia Southern University, Statesboro, GA 30460;
[email protected];
[email protected] Journal of Chemical Education • Vol. 80 No. 6 June 2003 • JChemEd.chem.wisc.edu
