An Integrated Lecture-Laboratory Environment for General Chemistry

Feb 2, 2000 - Chemistry 124/5 is one of four general chemistry course sequences taught at California Polytechnic State University,. San Luis Obispo (C...
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In the Classroom

An Integrated Lecture–Laboratory Environment for General Chemistry Christina A. Bailey,* Kevin Kingsbury, Kristen Kulinowski, Jeffrey Paradis, and Rod Schoonover Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, CA 93407; *[email protected]

Even though the department scheduler had attempted to link lecture and laboratory sections with the same instructors, we still experienced a discontinuity of time, place, and instruction in the traditional lecture–lab format. Although our lab sections held a maximum of 24 students, the lecture sections contained 100–144 students. When funding became available, existing space was redesigned to accommodate an integrated environment in the mode of workshop physics studio classrooms developed at Rensselaer Polytechnic Institute (4 ).

This paper describes the physical attributes and uses of an integrated learning environment for a large-enrollment general chemistry course sequence. The room was opened in Spring Quarter 1997 and 2000 students have passed through its doors since then. The facility is one in which experimentation, collaborative student involvement, lecture, technology, and individual attention can be maximized for more effective learning (1). With it we hope to foster a healthy spirit of pedagogical experimentation in a modern technological environment—education for a new millennium. See our Web site at http://chemweb.calpoly.edu/chem for links to laboratory experiments, current instructors’ pages, and other course materials.

The Room Existing space was redesigned for two integrated classrooms: chemistry and physics. Two prep rooms, one for each discipline, were included in the construction. As diagrammed in Figure 1, the chemistry facility has floor space measuring 30 × 80 feet. There are 32 student stations arranged in 8 clusters of 4 stations, 2 students per station, for a total capacity of 64 students per class section. A cluster is about 10 feet square. This means there are 64 students in one room for both lecture and laboratory. An instructor’s desk and computer station are positioned in the middle of the room with complete access both visually and physically to all parts of the room. Figure 2 shows a standard cluster and Figure 3 is a view from one end of the room. Each computer station is also equipped with a Vernier interface box with standard probes for measurement. We schedule the room for 6–7 course sections each quarter. Each section meets for 6 hours in the room. Classes run from 7:30 a.m. to 7 p.m. Monday through Thursday and 7:30 a.m. to 5 p.m. on Friday. Monday through Thursday evenings, the facility is staffed by teaching assistants for open hours, that is, for class-related computer work and tutoring. We have experimented with several variations on the length of time per class meeting as well as the sequence of days of instruction. This is facilitated by the fact that the room

History of Course and Facility Development Chemistry 124/5 is one of four general chemistry course sequences taught at California Polytechnic State University, San Luis Obispo (Cal Poly) in the Department of Chemistry & Biochemistry. The student clientele comes from the College of Engineering (Computer Science, Mechanical, Materials, Industrial, Environmental & Civil, Electronic) as well as from Architectural and Agricultural Engineering. About 1000 students are enrolled in these courses every academic year. Cal Poly is on the quarter system, that is, terms with 10 weeks of instruction and an added week for final exams. It is an undergraduate teaching institution, with lecture and laboratory sections taught by faculty, lecturers, and part-time instructors. We currently do not have a graduate program and therefore have no graduate teaching assistants. From Fall 1994 to the present, we have been revising the content of both the lecture and lab in Chem 124/5. The revised approach stresses materials science and the solid state (2, 3), the use of computers in laboratory for data acquisition, molecular modeling, tutorials, and simulations, and an increase in the expectations for student entrants to the sequence.

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Figure 1. Diagram of studio classroom showing detail of a cluster.

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In the Classroom

is dedicated to this course sequence. The current time configuration for most sections consists of three meetings per week: two are 2.5 hours in length and one is 1 hour. This allows us sufficient time for experiments, activities, and discussion and provides a convenient period for testing. As the faculty and staff become familiar with the possibilities inherent in such a facility, other courses have been scheduled in the studio, such as an upper-division biochemistry class on protein folding and modeling and individual meetings of physical chemistry. The room is also used for department workshops on computer training. The Environment

Figure 2. Close-up of the table in one of the clusters (see detail of Fig. 1).

There are two computer servers for the courses: a file server for class management and a Web server. A Macintosh Workgroup Server 8550/200 Power PC (64 M RAM, 2 ×2 GB HD, Tape Backup) and a Macintosh Workgroup Server 9650/233 Power PC (64 M RAM, 4 GB HD) fill these roles, respectively. Both servers are on an APC Smart UPS 1400. The Web server (http://chemweb.calpoly.edu) is also used for the physics studio classroom. The side counters and cabinets are used to store and supply common equipment. These areas also house six sinks with deionized water and eyewash fountains. There are two safety showers, one over each door, and all equipment and desks are accessible to the disabled. Electrical connections are placed beneath the raised floor, which consists of carpeted, removable tiles. Deionized water and helium gas lines pass above the dropped ceiling. The fluorescent lighting is recessed; it is usually unnecessary to darken the room because information from the instructor’s computer is delivered simultaneously to every student monitor via a Robotel M160 System for feeding simultaneous images to all classroom monitors. This is a “wet” laboratory environment. We use 1 M and 6 M HCl, small amounts of organics, and water solutions. Since we introduced computers into the traditional laboratory four years ago, we have not lost a single machine to chemical spills. This includes the monitor, keyboard, CPU, and mouse. Instructors and TAs are very safety conscious and the students are constantly reminded of the proper procedures to prevent and remediate spills.

Figure 3. View from one end of the studio classroom.

Instruction Each section is facilitated by a faculty member with the help of two undergraduate teaching assistants. Most of the teaching assistants are engineering students who have successfully completed the course sequence. Some are chemistry and biochemistry majors. Therefore students within a course section experience consistency of instruction and a number of human resources. The layout of the clusters allows easy access to every student and individual contacts are maximized. All course information, syllabi, and lab manuals reside on the instructors’ Web pages. Traditional “lecture” topics are integrated with experimentation, collaborative exercises, and the utilization of Web resources. Most lab reports are in the form of Excel documents designed by the instructors. Students fill in the required data, generate graphs and statistics, and compose conclusions in 196

the same document. They then use the “Hand In” function of the At Ease (Apple Network Administrator’s Toolkit) File menu to submit their reports. Since the server for the room is self-contained and secured, the students can email Excel documents to their own university or personal Internet accounts in order to work at home. Quizzes, exams, and other learning exercises are hand written. Collaborative Web assignments are also part of the instruction. Assessments before, during, and after the course are taken manually and through Web instruments. The assessments are currently being collated, evaluated, and further developed. Technical Support The chemistry studio classroom is one of five such facilities within the College of Science and Mathematics at Cal Poly. In addition there are two rooms for math, one for statistics, and one for physics. The statistics lab is located in a building separate from the other four labs. Two technicians manage all these environments with the help of student assistants. One of the technicians has the major responsibility for the chemistry studio. The prep room for chemistry has space for several technicians and teaching assistants to work at the same time and houses the servers for the room. It is important to note that adequate technical support is essential to the effective function of an integrated lecture–lab environment. We are fortunate to have excellent electronic, computer, and chemical technicians who function not only to support the curriculum, but who also help in the development of course and lab materials.

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In the Classroom Table 1. First-Quarter Traditional General Chemistry Course Lecture Topic

Laboratory

Review of equations, mole concept, Physical properties: boiling point, stoichiometry refractive index, gas chromatography (2 weeks) Thermochemistry

Emission spectra

Atomic theory

Titration (2 weeks)

Bonding

Compounds of copper

Introduction to organic chemistry

Reactions of organic compounds

Table 2. Integrated First-Quarter General Chemistry Topic

"Laboratory"

Diagnostic quiz

Excel graphing exercises

Thermochemistry

Heat of sublimation Heat of combustion

Nature of the atom

Emission spectra

Bonding: metallic, covalent, ionic

Solid-state modeling: cubic cells, ionic solids, and stoichiometry

Properties of metallic and covalent substances

Conductors, semiconductors, and superconductors

Nature of organic compounds Organic structure and nomenclature Building organic models Polymers IR spectroscopy

Organic analysis: unknown compounds and mixtures— Pure organic liquid: refractive index, density, and infrared spectra Gas chromatography: qualitative and quantitative analyses IR: spectra of common packaging materials

Curriculum—Past and Present Tables 1 and 2 give an overview of the more traditional curriculum for Chemistry 124 (the first-quarter course) taught prior to 1994 and the course as it is presented today. The curricular changes in the lecture and laboratory were developed during the period from the 1994-95 academic year to the opening of the studio facility in spring 1997. It is important to realize that the integrated pedagogy seemed to be a logical evolution of the curriculum revision. Instructional Examples The first topic covered in the first-quarter course is thermochemistry. The box compares the traditional and integrated approaches. It is important to note that students would most likely encounter two instructors in the traditional mode, whereas only one instructor is involved in the integrated pedagogy. Breaking up the laboratory with discussion and problem-solving sessions reinforces the empirical nature of chemistry, allowing for a discussion of sources of error and experimental limitations before proceeding to a more intensive part of the lab. Quick feedback on the statistical validity of the class submissions on sublimation encourages the students to work collaboratively on Hess’s law, for which each pair of students (one computer station) is responsible for a metal and the cluster of 8 students must produce the data for all the metals. Lab reports are submitted individually. Although the data, calculations, and results will be common, the other sections

of the report—purpose, format, conclusion (discussion of three sources of error, three things learned during the lab, and at least two questions which still remain)—are a student’s individual responsibility. The conclusions are some of the most insightful student feedback we have seen. The Web explorations are occasions for collaborative work in ever-expanding groups. We have used an initial Web assignment to acquaint students with the course. This exercise can be found in our Web site at http://chemweb.calpoly.edu/ chem/bailey/studiochem.html. The exploration using metals combines descriptive material with a practical introduction to the use of Web search engines. A table cluster is assigned a metal such as Al, Cu, Mn, or Cr. Then each pair of students at a computer station is assigned a particular search engine (Alta Vista, Excite, Infoseek, Yahoo). Students have to write out the answers to several questions. At the end of the designated search time, each cluster discusses the results and makes a recommendation with supporting statements about the best and the worst of the search engines. In addition, each cluster comes up with the most interesting and unexpected fact they could find about their metal. Brief oral presentations follow. (See http://chemweb. calpoly.edu/chem/bailey/studiochem.html). The idea of an ever-expanding collaborative exercise can be used in the development of bonding concepts for ionic salts, that is, learning the workings of the Born–Haber cycle. A pair of students is given an envelope containing strips of paper with equations. The goal is to put together the equations, Hess’s-law fashion, to find a “target”—the lattice energy of a particular salt. Each of the four groups in a cluster has a different salt comprising monovalent and divalent ions. From pooling their information the cluster should be able to hypothesize a periodic relationship of lattice energies and draw up some general rules. The class enjoys this activity and seems to be able to grasp the concepts involved, especially in comparing ionic compounds with metallic and covalent elements and compounds. Incentives involve extra credit for being the first correct group of theoreticians. In the second quarter kinetics is introduced through some clock reaction demonstrations. This is followed by data collection using computer-interfaced pH probes (Vernier) to follow the hydrolysis of tertiary butyl chloride. Clusters work at assigned temperatures and results are exchanged between clusters in order to produce the Arrhenius relationship.

A Comparison of Pedagogical Approaches TRADITIONAL APPROACH Lecture (ca. 3, 1-hour) Demonstrations Assigned readings and problems Laboratory (3 hours)

Heat of sublimation Hess's law—Heat of neutralization

INTEGRATED APPROACH Demonstrations Work sheets and discussion First lab: Heat of sublimation; Electronic submission of data Discussion and problem-solving Second lab: Hess's law—Heat of combustion for Mg, Al, Zn Web explorations: Nature and properties of metals

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We are developing an environmental analysis theme for the second-quarter course because most of our experiments involve spectrophotometric analyses. For example, in conjunction with a discussion of solution concentration terms, we combined analyses of nitrite and sulfate measured in ppm with Web explorations on EPA air and water standards and the health effects of certain contaminants. Overall, we find that the release from the constrictions of time and place found in traditional lab–lecture formats has stimulated creative approaches to collaborative work and the integration of Internet resources with the curriculum. Student Response Although our assessment program is still in its formative stages, we have gathered enough data from evaluations of the facility and curriculum to see that this approach is extremely well received by the students. A very small sample of student comments: “I think that the course work really challenged me to work harder and so made me really want to learn.” “The computers made the class go faster. I have never been in a class where computers played such a vital role.” “I like the studio chemistry setup and would like to take more classes in this type of classroom. It is more like what I expect to encounter in the future.”

The students have also offered some valuable criticism on presentation and conditions in the room. “The room was always very hot.” (The room has been air-conditioned.) “Only one problem: the instructor’s microphone needs some adjustment so that it will not get disconnected all the time.” (We have converted to a wireless system.) “I liked having the syllabus on the Web, I would have liked to have had a running total of the points I received in my folder so I could compare and see what grade I was getting.” (We are pilot-testing the use of coursemanagement software during the 1999–2000 year.)

Overall, there seems to be a sense of community engendered by the entire environment. We look forward to the results of longitudinal studies to confirm whether this approach has strengthened technological and laboratory skills, improved content retention, and increased appreciation for the role of chemistry in the core curriculum of the engineering disciplines. A Word to the Wise Instructors new to this integrated form of teaching tend to fall back on traditional lecturing. This has not worked at all in this environment. Lecturing should be limited to perhaps 30 minutes at most. It is advantageous to have the students physically move around during every long class period. This keeps their attention and involvement. A break is a necessity during the 2.5-hour class periods. Sometimes students will stay to work at their computers, but they are aware that they had the opportunity for a break. Something to note: we have had many visitors and observers at the facility since its opening; most are unannounced 198

to the students (the faculty member teaching at the time is usually given notice). To a person, all have remarked that the students are “to task”, whether in an experiment, individual work, or group work. The students are eager to show the visitor what they are doing and learning. There is a sense of involvement that we have not experienced in the traditional mode of instruction. Future Development With the pedagogical opportunities that this facility gives us, we are able to establish an experimental teaching environment where we can study the effectiveness of various modes of instruction. We are trying different types of collaborative learning experiences, working on multimedia presentations, incorporating assessment instruments into Web-based formats, and working on the correlation of instructional goals with valid assessment tools (4–7 ). Conclusion This integrated facility is a unique prototype for general chemistry instruction, especially for large-enrollment courses. It is technologically current, versatile in accommodating discovery-type classes, and conducive to collaborative exercises, and most importantly, it promotes a cohesive mode of instruction that allows experimentation to be interfaced with concept development. Not only are students working together more effectively, but faculty and staff also work in concert to promote a curriculum that can attune itself to the individual as well as the masses. Acknowledgments This entire project and its future depend upon a foundation of intellectual, professional, and financial support. The reconstruction of facilities and purchase of computers and equipment were financed by the Chancellor’s Office of the California State University System, the President, Warren J. Baker, the administration of California Polytechnic State University, and the Dean of Science and Mathematics, Philip S. Bailey. A modern university runs through the expertise and collaboration of students, faculty and staff. Our highly competent technical colleagues are John Teclaw, Jim McLaughlin, and Jack Collins. And to all of our undergraduate TAs—thank you for your enthusiasm and dedication. Literature Cited 1. Committee on Undergraduate Science Education, National Academy of Sciences. Science Teaching Reconsidered; National Academy Press: Washington, DC, 1997. 2. Ellis, A. B.; Geselbracht, M. J.; Johnson, B. J.; Lisensky, G. C.; Robinson, W. R. Teaching General Chemistry: A Materials Science Companion ACS Books; American Chemical Society: Washington, DC, 1993. 3. Gulden, T. D.; Norton, K. P.; Strecert, H. H.; Woolf, L. D. J. Chem. Educ. 1997, 74, 785–786. 4. Wilson, J. M. Phys. Teach. 1994, 32, 518–523. 5. Bailey, C. A.; Kulinowski, K.; Paradis, J. Studio Chemistry: A Feasible Environment for Large General Chemistry

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In the Classroom Courses? Presented at the symposium Developing Instructional Technologies—Where Is the Cutting Edge; 215th National Meeting of the American Chemical Society, Dallas, TX, March–April 1998. Paper 091. 6. Bailey, C. A.; Kingsbury, K.; Kulinowski, K.; Schoonover, R. General Chemistry in a Studio Format; Presented at the Cancun International Congress, Mexico–Fifth Chemical Congress of North America, Cancun, Mexico, November 1997. 7. Bailey, C. A.; Baker, B.; Paradis, J.; Scholefield, M. New En-

vironments for Old Lectures. Presented at the 217th National Meeting of the American Chemical Society, Anaheim, CA, March 1999. Paper 831. 8. Bailey, C. A.; Kulinowski, K.; Paradis, J. Studio Chemistry: A Feasible Environment for Large General Chemistry Courses? Presented at the symposium Taming the Whale: Innovations for Large Chemistry Courses; 215th National Meeting of the American Chemical Society, Dallas, TX, March–April 1998. Paper 634.

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