A Touch of Reality in the Sophomore Organic Laboratory M. K. Schumm Montgomery College, Rockville, MD 20850 A numher of years ago I used a laboratory text for my organic chemistry course which introduced each exercise hy describing a situation which would require a research chemist in an academic, government, or industrial setting to conduct such an experiment (1). This same lahoratory text also had an excellent set of guidelines for maintaining a prufessionalquality laboratory notehook. Over the vears I have elaborated on the idea of bringing . -a touch of realism into the organic lahoratory course. I have develoned two laboratorv. .oroiects to give an exoeriential in" troduction to two very different situations encountered by professional organic chemists: 1) a simple synthesis with a specific research objective, and 2) a multistep synthesis with a cost-effective commercial product as its ultimate goal.
These projects are designed to test synthesis and purification skills and also to give first-hand knowledge of how professional chemists record and report the results of their experiments. For the first project I have selected a simple synthetic procedure, the acid-catalyzed dehydration of an alcohol (2-4). This oroiect is done in the first semester of our course. About two weeks before the experiment itself is scheduled, students are given a list of about 15 alcohols, generalized instructions for conducting the dehydration, andsome additional guidelines. From this information they must 1) decide on an ohjective for the experiment; 2) choose an alcohol appropriate to meeting that objective; 3) make any changes in procedure which may he necessary; and 4) submit a typed proposal stating the selected ohiective and outlining the exact procedure to be used.
Students are encouraged to consult with me if they encounter any difficulty. Once the ~. r o. ~ o shas a l been aporoved they can begin . the .. experiment. Results are analyzed by gas chromatography and IR spectroscopy. Purified reference samples of the major alkene products are provided to help students with the analysis of their results. When the experiment has heen completed, a typed report suitable for suhmission to a scientific journal must he written. A rough draft is evaluated either by me or hy a fellow student. Reports must include (1) a short ahstract, 50 words or less, (2) an introduction which includes a precise statement of the purpose of the experiment, (3) a list of
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Journal of Chemical Education
equipment and chemicals used, including make and model numher for instruments. (4) an outline of the orocedure used. (5) tabulated results, (6)a discussion of the results obtained in the lieht of the stated ohiective. (7) a conclusion, and (8) a .
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20-25'10 of t'he laboratory grade.. The second project is the multistep synthesis of an organic compound. It is done in the second semester. Typical syntheses can be found in most organic laboratory manuals ( 5 4 ) . The ohjective here is to evaluate the efficiency of the synthetic scheme and calculate the overall cost of the final product. Up to this point in their lahoratory course, the students have been required to keep a record of the amount of time spent in the preparation of each of the substances which they have synthesized. This includes time spent in notebook preparation and in writing up their results. For the multistep synthesis the students are told to "pay" themselves $3.50hr fur the total time spent on the synthesis. To enable them to calculate the other costs incurred, they are given a rough estimate of the overhead for use of the lahoratow (about $50hr) and orovided with chemical supply catalogs so that they can determine the cost of all reagents and expendable equipment. These data are then used to calculate the cost per gram of the final product. Once again, a formal report similar to the one outlined for the first semester's project, but adapted to the changes in ohjectives, is required. The costs reported range from $250 to over ".
These experiments, though demanding and time consuming, are well received by the students, who often become quite involved in the exercises Literature Cited Ill Roa~nhlart.D. H.. and Davis, C. 'P.. "1,abnralury Crarse in Orwnic Chemistry." Allyn and Racun. Roram. 1971. 121 Roberts. K. M.. Gilhert,.l. C.. Rcdewald, I.. R.,and Wingrove.A.S.."Madern Experimental OrpanlcChemistry.":irdod.. Holt. Rinehart. and Winston. N E WYcmk, 1979. pp. 151-164. l:ildacohs, T. L.. Truce, W. E.. and Rokrtsun. C. R.. "1.aboratory Practice of Organic Chemistry? 5th ed.. Macmillan. NPW Ynrk, 1974, pp. 253-25h ill A u k A , "Techniquosand Rrprimenl* hrOrgnnicChemirfrv." 4thd.AUvnand Bacun. Rockleigh. NJ. I9X2. :149-:165. i51 Rnherts. H.M.. Gilhert. J. C.. R~dcwald,I..R..and Winmve.A. S.. " M u d m ExperiOryanir Chemirtry.":ird ed.. Hnlt, ninehanand Winston. NevYcxk. 1979, pp. 359-390. I61 Aull.A.,"Torhniquossnd Exppriments icr 0rganwChemistw,"4thdddAlI)n)n)nd Bacon. Rockleigh. Nd. 1983, pp. 4fi7-498
