edited bv
view from my ckmoom
GARYE DUNKLEBERGER Carroll County Publlc Schwls
G--.E;
Introductory Organic Chemistry with Instrumental Analysis A Third Year High School Chemistry Course John Liebermann, Jr. T. C. Williams High School, Alexandria, VA 22302
This article descrihes an advanced high school chemistry course that exposes students to a wide variety of modern instrumental techniques. The course is the final course in a three-year chemistry sequence offered a t T.C. Williams High School in Alexandria, Virginia. The school has a heterogeneous student body of approximately 2400 students with varying ethnic backgrounds, ability levels, and occupational Over the last 10 years, more and more students have begun taking their first year uf chemistry earlier in their highschool rarrrr. We found ourselves with a significant numhw of stu-
dents who, at the start of their junior and senior years, had already finished two years of chemistry. Many of these students had career objectives that would necessitate their taking a t least one more chemistry course a t the college level. To better prepare this group of students for college courses and enrich their science experience by providing laboratory experience not available in most high schools, a third-year chemistry course was introduced. A course stressing organic chemistry seemed a logical choice for three reasons. First, instrumentation that would greatly compliment a study of organic chemistry was available. Sec-
Laboratory Syllabus Activity Melting poink Recrystallization Exh-Bction of mandeiic acid Separation of an acid. a base. and a neutral compound Preparation of acetylsalicylic acid Separation and purification of a mixture of Mexane and pxylene by fractional distillation Determination of the Specific rotation of sugars The inversion of sucrose-a polarimeteric kinetic study Preparation of cyciohexene Quantitative infrared anaiysis of xylene mixtures Qualitative and quantitative determination of iron in vitaminmineral tabletsa comparison of methods
InstrumentationUsed
Reference
mel-temp (Labmatory Devices)
Activity
(4. P. 35)
Preparation of isopemy1 acetate
IR (Beckman, IR33)
(3, P. 31)
TLC analysis of analgesic drugs
r e f r a c t m t w (Abbe) GC (Carle, 6500T)
(5, P. 13)
polarimeter (Cenco)
polarimeter (Cenco)
IR (Beckman, IR-33) IR (Beckman. IR-33)
(61
direct reading spectroscope (Vreelaod, mcdel 7) AA (Varian Techtron. 1.000) UV-visible scanning SpeCtrOphMometer (Varian, series 634) visible spectrophotameter (Sargent-Welch Chemanal System)
(7.8)
lnsrmmentationUred
Reference
iR (Beckman. IR-33)
(3, P. 86)
HPLC analysis of analgesic tablets
HPLC (Varlan, multicomponent)
(9.
Analysis of a commwcial furniture refinisher using NMR
NMR (Varian, EM-300X)
(11)
An oxidation-reduction schema: borneoi, camphw, isaborneol
IR (Beckman. iR33) NMR (Varian. EM-3OOX)
(3. P. 151)
The preparatim
IR (Beckman, IR-33) NMR (Varien. EM-300X) Mass Spec (Varian. EM-600)
(la
and specha1 anaiysis of toiuene-cid using iR, NMR, and mass spec
Volume 62 Number 4 April 1985
14
321
ond, an introduction to organic chemistry beyond that in the introductory coursvs wouid surely help those studrnts with medical cnrrw aspirations. Finally, imporrant principles from thth :tmer;~l chemistry courses could he reviewed and reinforcrd using examples from the re;~lmof organic chemistry. Course Description The averaee enrollment in the course is between 15 and 20 ~~" students. Advanced placement chemistry is prerequisite. Students enroll for two 50-min periods and receive two credits for the year. On lecture days students report for only one of the two periods and eat lunch during the other period. On lahoratory days students eat lunch for the first 30 min of the double period. which leaves 75 min for lab. Most days are spent i n the lab. Lecture follows the text "Organic Chemistry" by Morrison and Boyd ( I ) . The first 12 chapters of the third edition are covered in some depth. Other topics covered in the lecture that go with or complement the laboratory portion of the course include NMR, IR, and UV visible spectroscopy, mass spectroscopy, AA, chromatography (thin layer, GC, HPLC), fractional distillation, refractometry, and polarimetry. A week or more is spent on major instrumental techniques such as IR, N M R , nnd mass spec before being utilizril in the lab. For interprrmtion oithe data ohtained from the latter instruments, reading is alsu assigned in the text by Silverstein et al. ( 2 ) . Lahuratory artivitles are taken from diiierent sources. However, studens have a basic rtfcrence manual ( 3 )to which they refer for lah techniques and barkgn~undmaterial. The accompanyin:: tdblc indicates the lahoratory syllahus and the instrumentation availnhle. Students perform most lahoratory activities in pairs because of the class size and equipment limitations. When an exercise involves a major instrumental technique \i.e.. NMH),twoor more artivitirs will he in progress at the same time so that everyone has something to do while waiting for a turn on the instrument. Within reason, students are all given all the time needed to finish an activity. Many work a t other times during the day to meet a deadline or to avoid a crowd a t an instrument. The highlight of the entire year is the final exam. Each ~
~
~~
~
~
school chemistry teachers from around me country open their through thls feature, tor all to see. Teachers are invited to share their techniques,methods. and ideologies.Contributions should be sent to ltw feature editor. High
Clasrm.
322
Journal of Chemical Education
student is given an unknown and approximately three weeks to identify it using traditional qualitative analysis and instrumentation. A student's exam grade is based on the quality of the experimental and theoretical argument he or she makes for a particular structure in a formal, written report and not on the proper identification of the unknown. (Experience has shown that almost every student correctly identifies his or her unknown.) The enthusiasm with which these hiah school students work on their final exams is tremendous,and from the instructor's viewpoint. makes the work which aoes into teaching a course like this seem worthwhile. Conclusion
This course provides extensive exposure to realistic lahoratory techniques. Students spend enough time engaged in routine lahoratory activities to become comfortable in this kind of setting. Besides use of the instruments already described, routine activities include the use of standard-taper glassware kits, the preparation of standard solutions, and the proper use of pipets, to name a few. One imoortant outerowth of the course is student research projects. These projects are in addition to the regular course work and are carried out hv students still enrolled in the course and by those who have already completed the course. The oroiects have a record of success in such science comoetitions as the Westinghouse Science Talent Search and the International Science and Enaineerina Fair. The most important resultfrom this third-year course is tlie unusually. large . number of students who enter promams of study in college leading to degrees in chemistry,ch&ical engineering, and other chemistry-related fields. Several past students &e also presently in graduate school or medical school. Literature Cited (1) Morrision, R. T., and Boyd, R. N., '"Organic Chemistry:' 3rd ed.. AUyo and Bsmn.
n-t""
I.,%
(2) Silverstein, R. M..Baaskr,G. C.,and Morril1.T. C.,"SpeNomNicIdentification of OrganicCompauods." 4th ed., John Wileyand Sons. NeuYork, 1981. (31 Pa%, D. L,hpman,G.M.,and Krir G. S.,Jr.,"lntradudiontOOrganieLaborbotory Techniques,' 2nd ed.. Saunders College Publishing. New York. 1982. (4) Linstmmborg, W. W.,md Baungartcn,H.E"O~anicExperime"~foraBrief Cow," 3rd ed.. D. C. Heath and Company. 1974. (51 Lang8joen.A. N.;'Laborstory Manual for OlganicChemistry: ABriefCourae,"John Wilw and Sons. New York. 1975. l6I veer&. H..J. C-. EDUC.,43.319 (19661. (71 Pinnell, R. P., J. CHEM.EDUC.,57,444 (1980)
