Teaching Qualitative Organic Chemistry as a Writing-Intensive Class -
Christine K. F. Hermann Box 6949, Radford University, Radford,VA 24142
Qualitative Organic Chemistry is a course that many schools have dropped from their curricula. Reasons for not teaching a n independent qualitative organic chemistry course include the idea that other courses need to be taught instead, or that the course is too time-consuming for the faculty member. At some schools, qualitative organic chemistry comprises the last semester or quarter of organic chemistry lab. Several articles (1,2) have discussed the particular ways that qualitative organic chemistry has been taught a t various colleges. At Radford University, undergraduate students are encouraged to take this course as a chemistry elective. I have been teaching the course biannually for the past eight years. During this past spring semester, I taught the course using a writing-intensive a ~ w o a c hbased , upon ideas that I '(earned through my pariiEipation in the G t inrr across the Cumculum promam at Radford Universit.~. Below, the course is desmbed and the use of writing-&tensive techniques are discussed. Description of the Course Qualitative Organic Chemistry, Chem 451, is offered every other year in the spring semester. The prerequisite for the course is one year of Organic Chemistry. The course is three credits, with one hour of lecture and six hours of lab per week. Each student is given 10 unknown compounds and, in the course of the 15-week semester, has to identify each compound. The student is allowed to work in the laboratory during the school day as long as a chemistry faculty member is available in the department. Discussion of the Course The cumulative grade for the course was based on the lab report sheets discussing the identification of the unknowns (40%),the formal lab reports (lo%),the notebook (lo%), the journal (lo%), the midterm (15%), and the final (15%).As a writing-intensive class, the formal lab reports and the journals replaced homework assignments. The lecture portion of the class focused on the different methods that each student may use to identify the compounds. In the first lectures, infrared spectroscopy, nuclear mametic resonance sDectroscoDv. and mass s~ectrosco~v were discussed in detail, inc~udi;;~ the theory,'interpre& tion, and use of the instruments. The students were checked out on each instrument, and were expected to use the instruments in order to obtain the spectra of their compounds. NMR and FT-IR spectra were required on all 10 compounds, and mass spectra were required on two of the samples. The students were not allowed to do computer matching of their spectra with the spectral libraries available in the computer memory of the spectrometers. However, the students were allowed to use the Aldrich IR and NMR spectra books. Other methods, such as elemental analysis, solubility tests. classification tests. oremration of derivatives. soecific gravity, optical rotatiin, &romatography, and v&&s distillation techniques were discussed in the lecture. The students were expected to use the solubility tests and a t least one classification test on all unknowns. Elemental
analysis, done by the sodium fusion method, was required for one specific unknown and recommended for another samole. The determination of s~ecificmavitv also was requirkd for one particular unkndwn. The students were told that the first unknown was a carboxylic acid. From the titration of the carboxylic acid, the equivalent weight, and therefore, the molecular weight can be determined. With the molecular weight, melting ooint or boiling ooint. and the IR and NMR soectra. the sample was id&fied'easily. The early samples' were kasy to identifv. while the s a m ~ l e eiven s later in the semester were pro&essive~ymore h i f i h to identify. I had purposely chosen unknowns that were listed in the derivative tables of the textbook (3).
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Writlng-Intensive Portion of the Course The weeklv iournal and the formal lab reoorts were the devices thatlvkre used to transform the couise into a writing-intensive course. The journals were used in addition to the standard laboratory notebook. The journals were due each Fridav. and formal lab reoorts were reauired on the first five u&own samples, In the weekly journal, students had to make entries in each of the following four categories: accomplishments, failures, successes, and plans for next week. The accomplishments could include spectra that were obtained, melting points or boiling points obtained, or solubility tests that were done. The failures could include the derivative orocedures that did not vield a oroduct or a oarticular instrument that did not function properly. Successes could include the ~ositiveidentitv of an unknown or a classification test that determined tge absence or presence of a functional group. Since the students were allowed to work in the laboratory at any time during the day, I used the journal as a way of keeping track of the students' progress in the course. These journals were done in a standard spiral notebook. The students had to write in complete sentences. For the formal lab reports, the students took the raw data from the graded worksheets and developed it in Daragraph form. ~ i i sections e of the formal were the introduction, the results and discussion, the spectral information, the experimental, and the reference section. This format corresponds closely to that required by the American Chemical Society for publication in journals. The papers were graded as to content, grammar, punctuation, and the orderly flow of ideas. The paper had to be written in such a manner that another student could duplicate the work. Evaluation of the Student's Work During the course of the semester, the four students worked hard in the laboratorv analvzine their unknowns. I frequently checked their b&ng points and their interpretation of the spectra before they turned in the report worksheets. Of course, I was called on frequently to help the students use the IR and NMR spectrometers.
Volume 71 Number 10 October 1994
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The journal entries improved with time. Initially, the students had very little to report. I feel that the journal made the students account for what they had done each week and helped them plan ahead for the next week. The formal laboratory reports also improved. Students sometimes did not include a procedure or neglected to discuss the results. organization in the experimental portion of the papers occasionally had its problems. For instance, the derivative procedure appeared before the classification procedure in some papers. Each of the four students identified all of the unknown compounds correctly. The written work that was turned in was of high quality. Therefore, these students earned correspondingly high grades for the course. Evaluation of the Course The Qualitative Organic Chemistry course requires a lot of time from the faculty member. However, I feel that it is time well spent, because the students benefit greatly from the experience. The students typically ask a lot of questions, including clarification of procedures, and help with the instruments. Because the course is not as structured as the basic organic chemistry class, the students have to plan out their time in the laboratory. They enjoyed the freedom of working on their own. They frequently consulted with each other as to the best experiments to do. The journal served its purpose, because it helped me keep track of the students'progress in the class. In a previous class, the students quit working near the end of the
862
Journal of Chemical Education
semester and failed to turn in their unknowns and uotebooks. The students learned how to write papers in a professional manner by doiug the formal lab reports. This is valuable experiencefor those students that are planning to attend graduate school. These formal lab reports were different from other papers that the students may have done, because these formal lab reports were based upon work that the students had actually done and were written in a format appropriate for publicition in a chumistry journal. Overall. I feel that the inclusion of writine assimments in this chkmistry class is a benefit for the st;dentk his or her future classes, graduate school, or job. Acknowledgment I would like to thank the students in the Chem 451 class-Lynn Vitale, Chris Olha, Kevin Shockley, and Steve Harvey-for doiug the work discussed above. I also would like to thank the faculty of the Writing Across the Curriculum program a t Radford University for suggesting ideas to try out in the class. Lastly, I thank the chemistry faculty at Radford University, for helping these students in their studies. Literature Cited 1. Zubrick, J.W J Cham.Educ 1992,69,38?. 2. Zieger,H.E.J.C k m . Ed-. 1993,?0,230. 3. Shnner,R.L.;&on, R.C.; Curtin, D. Y.;Marrill, T C. The SysBmofieIdanlifliflifllion of Ogonk Compounds: W h y : New York. 1980.
