A Chemistry (Methods) Course for Prospective
and in-Service Teachers E. K. Mellon Florida State University, Tallahassee, FL 32306 The College of Arts and Sciences of the Florida State University recently received permission from the Florida Board of Regents to offer a BS degree in secondary science1 mathematics teaching, leading to teacher certification in various scientific fields. Each deeree concentration requires the usual liberal studies c o ~ r s e ~ ~24 l usemester s hours in education courses (offered ~ r i m a r i l vin the Education College) including a 12-houriniernship:~hephysics-chemistry deeree reauires mathematics through Calculus 11 and either 22'hours in chemistry and 17 h o u r 2 n physics or 16 hours in chemistry and 23 hours in physics. The biology-chemistry concentration offers two options: 24 hours in chemistry and 21 in biology or 21 hours in chemistry and 24 hours in biolow . The deeree nroerams are coordinated bv the Office of "" Science Teaching A k v i t i e of the College df Arts and Sciences. In this connection the Florida State University Chemistry Department has developed a dual-level teaching-methods course, CHS 4450C/5455C, "Inorganic Chemistry for Science Teachers". The senior-level track, CHS 4450C, is designed for undergraduate majors in the program, while CHS 5455(:, the beginning graduate-level track, is for in-service teachers. Hoth tracks require a prerequisite of one year of general chemistry, and neither duplicates already existing offerines. .-~ - ~ - -T h e undereraduate students in CHS 4450C present a number of already published demonstrations in a microteachine settine. whereas each in-service teacher in CHS 5455C ievelops"i previously unpublished demonstration. and sutnniu a a a n u s c r i ~ describina t - it for publication in a science journal. The usual "methods course" is tied closely to the internship experience and attempts to span several of the sciences offered in high school. In contrast, the intent in "Inorganic Chemistry for Science Teachers" is to present chemistry content, specifically the chemistry of ions in solution, using exemplary teaching methods. The new course was first offered duringasix-week term in the summer of 1986. Four experienced, in-service teachers enrolled, each for the graduate-level track. Four 3.5- to 4hour sessions were scheduled per week for a total of 26 meetings, amounting to 32.5 classflahoratory hours per credit hour. Formal lecturing (including many lecture demonstrations) was completed during the first two class meetings. The next five weeks were spent in the laboratory, on field trips, and in infrequent ad hoc lectures-perhaps discussions is the better term-scheduled only when students requested them. Even the experienced teachers enrolled in this course encountered occasional difficulties in the interpretation of aqueous solution observations, and these difficulties led to the scheduline of i m ~ r o m ~class t u discussions. During the final week ma&.cri& describing the studentdeveloped demonstrations were prepared for publication. ~
~
- .
-~~
~
~~~
~~~
~~
~
~
~
~
-
~~
Presented at the 193rd ACS National Meeting, Denver, April 5-10. 1987, paper CHED 154. 786
Journal of Chemical Education
Student ~erformancewas evaluated on the basis of weeklv take.homePxaminations covering both course material and outside readinrs. A reading room, stocked with hiah school texts and labo&ory manu&, college-level generaland inorganic references, and reprints, was maintained. Formal lecture topics included: 1. Laboratory safety and waste disposal ( l , 2 )
2. Keeping a laboratory notebook the way research chemists do it (3)
3. Searching the chemical literature: Chemical Abstracts (4) 4. Preparing manuscripts for publication (5) 5. Test and examination construction:testine- for more than recall 16)
6. Professionalism, including criteria usrd in selecting tearhers for
regional and national teaching awards
7. Educational terhndagy (71 8. Learning theory (8)
9. Ethics, relations with students, professional Liability (9) 10. Escaping from "cookbook" laboratory experiments (10)
Critical to the success of a course of this sort is the choice of the program of exemplary Here one is faced . . experiments. . with the ihoice between using an already-prepared course sequence (11) or of producing such a course from single puhlished or locally produced experiments (12). We chose the former alternative, updating several of the experiments that originally appeared in A Course in General Chemistry by William C. Bray and Wendell M. Latimer (13).This text presents the laboratory portion of the 1940 general chemistry program at the Lniversity of California, Berkeley, and was developed during the period 1912-1940 by a group of faculty led by G. N. Lewis, and including W. C. Bray, J. H. Hildebrand, and W. M. Latimer. Hildehrand (14) has summarized the philosophy of the course: We have been inspired by the opportunity offered by a fundamental course to present science in such a way as, first, to win for scientific careers the keen-minded students who are repelled by the drudgery and memory work of the old-fashioned course in descriptiie chemistry; and second, to encourage the average student to adopt the scientific attitude towards his everyday problems . . . . We have heen convinced that. in order to attain these ends, the laboratory work must be the central frarurp of the course, and that it must involvr thr solution of prohlemr rather than the mere performance of illustrariw experiments . . . . Our choice of the Bray-Latimer experiments was dictated by the following considerations: The experiments cover the chemistry of ions in solution-ionic reactions,strong and weakacids,indicators, reversihility, neutralization, hydrolysis, solubility, am~hoterism,complexation, redox, . . chemistry of specific ions, separa&ons--content areas where prospective and in-service teachers need reinforcement. The experiments are true ezperiments, where the results are not known in advance, rather than vertification exercises. Many ofthe experimentsmay be campletedrapidly,while most of the remainder can he speeded up by the elimination of timeconsuming filtrations and multiple dilutions. The experiments are easily adaptable to the microscale.
.
The experiments require careful observation and laboratory note keeping, and the interpretation of later exp~rimentsfrequently requires referenre to observation made earlier. Predictions of untried experiments are frequently required. Finally, the experiments are fun to do, surely a most important feature of an exemplary laboratory program.
"... labs are very different to the kind normally done in undergraduate work . .. at first.. . vou . . . feel . orettv. uncomfortable . . .
The Bray-Latimer experiments required modification. Time-consuming, successive dilutions were deleted, and buffer solutions provideainstead. Gravity filtrations were replaced by centrifugation-decantation operations, and the scale of the operations was reduced in consonance withmodern waste-dis~osaldictates. The follo&g objectives of laboratory instruction in chemistry owe much to those of H. I. Schlesinger (15):
Literature Clted The bibliography that follows is meant to be selective, uresentina references unique t o a chemistry teaching-methi d s course.
.
.
Reinforcement of lecture content Trarning in laboratory manipulation skills Proviion of positive motivarion toward the study of chemistry Facilitation of the development of intellectual skills
One definition of an exemdars laboratory program is one that stresses all four of these objectives rather than the first qualifies as exemplary two onlv. The Brav-Latimer program . . accord& to this definition. How did the students evaluate the course?Their opinions were sought during the final week. Here are student perceptions of benefits derived:
"... better understanding of equilibria in aqueous solution .. ." "... I Learned more inorganic chemistry in this course than any other chemistry course I've taken .. . ." "... chance to review disposal and safety procedures ..." "... field trips-exposure and updating (i.e., glassware safety, integrated video disc computer) . . ." ".. . refreshed lab skills . .." ".. . experience in developing and submitting article for publication . . ." and here are excerpts from their overall evaluations:
". . . working in the labs .. . helpful, beneficial ... selfpaced = good .. ." ". .. First course . .. for professional development .. . that I can directly apply to the classroom .. . more useful to high school chemistry teachers (and prospective chemistry teachers) than all the'education' courses combined . . ." "... excellent . .. learned a lot and improved my competency asa chemistry teacher . . ." "... open, free exchange of ideas .. . low anxiety atmosphere . .. enhanced learning and made the experience a pleasure . . . components chosen for inclusion in the course were well selected and represent important areas for prospective teachers to consider
.
.. .
u
Howwer,onre you realize that you havegot tu be thinking about and quertiming each obs~rvationyou make, the whole experience becomes more meaningful . .. ."
I. Council of Stelr & m r c S u p w m n Srh.01 Sc.snre Lobamlorwc A Cuids to Srms Hoaordura S u b e n n , * \ 1's Omsumer I'rrduct S - l ~ t vO>mmm.on. Washlnaum. Dl-. 1961 Thissupplement tr ih. NIOSH Mnnvaivi9alel) a n d H d t h H a r a d i i n thr Srhl "1 srlm.l 1.ahnretory" v p r l a i * i m ~and sorage rtiummrndwonr for of safety rimmmendationa. It was common reagents as well as aieuil-headed reviewed by the ACSCommittea on Chemical Safety, Chem.Eng. Neua 1985,63(21, 72. Single mpies may be obtained free of charge by writing the Directorate for Health Services. U.S. Consumer Product Safety Commis~ion.Washington, DC 20207. Information about ordering in quantity may be obtained from the U.S. Government Printing Orfiee, Washington, DC 20402. or from F. D. Kizer, Rt. 2, Box 637, Leneester, VA 22503; (804) 462-7371, Another valusble reference, particularly for ite mverage of waste d i s p o d and the Resource Conservation and heovery A d (RCRA), is Safety in Acodamic LoboroloGs published by the Americao Chemieal Society Single mpiea are fcee and it may be ordered in bulkat S1.W par copy from ACS, P. 0. Box 57136, West End Station. Warhington.DC 20037. 2. Anon. The Sci~ncelnstruclorsSn/~rSss~ss: 1986Chamieol ColoioglRo/e~~nce Manual: Flinn Seientifie Ine., PO. Bm 231. Batevia. IL 60540. This ia the aoura eonoulted by many school tasehenfor thesafe storage,use, and disposdof~esgente. 3. Kanare, H. M. Writing the Loborntory Notebook Americsn Chemical Saiety: Washington, DC, 1986. 4. Anon.How To Seoch h i n t e d CA:Chemieel AbatracteSeniice.P.O.Boi 3012, Columbus, OH 43210. 5. Anon. How To Prepore o Monuarripf; Journal of Chemical Education. 1983. Available from A.M. Saquia, High Schwl Editor, Journal of Chemieal Education, Miami University-Middietoam. 4200 East University Boulevard, Middletom. OH 45042. 6. 0ngley.P. A,; Houk.C.C. J. C h e m . E d u 1969.46.830. 7. Crosby,G. A. J. Chm.Edue. 1985.62.723 Achemistlaoksateduestionaltechnology. 6. Good, R. G. Holv Children Learn Slieneo: MscMillan: New Yark. 1977. Gwd, R.; Mellon, E. K.; Kromhouf, R. A. J Cham. Edur. 1978.55.688; Gmd, R.;Kromhout, R. A.: Mellon, E. K. J. Chem. Edur. 1975,52,146. Among r e a n t learning theories, that of Pisgethes heldwideappalfor chemiste,and thelatter tvoartielesdesiwith bin theories. 9. Sweency, T. L.J. Chem. Educ. 1977,54.134. 10. Me1lan.E. K. J. Chsm.Educ. 1978,55,517. Chemistry uperimentafrom theliteratwe are categorized according to several degrpps ofileribility. n. It is difficult to retrieve older laborstory manuals due to their ephemeral nstme. However,threevery differentcramplesmmotomind: Abraham,M. R.; Psvelich, M. G. Inquiries Into Chemistry: Waveland Press, Inc., P.O. Bm 4W, Proswct Heinhe. IL 6W70, 19e4. Hem is a set of "guided inquiry exwriments" based on learning fhwry research. Gray,H.B.;Crawford,T.H.Pmjecf ACAC: WorthPublishers: Near York, 1969.Thistextpresenteaseriesofresearch-flavarederpedmentedeatingruIth transitionmetalseetylsectonates. Y o u n d A.Procticein Thinkin8;Prentiee-Hall: Englewood Cliffs, NJ, 1958. Young's famous laboratory course ia devoted to the formation of testable hypotheses. 12. Bunce,S.; Allen, C. B.: Zubriek, J. W. Pmjacf Chemlob: AnnotatsdLisf oiChemlalry Experiments, 2nd d . ; American Chemical Saiety: Washington, 1987. This reference lids and describes all chemistry experiments published in this Journol batween 1957 and 1984. It isavailable from theAmerieanChemicalSaeiety,Edveation Division, 1165 16th Street N.W., Washington, DC 2W36 st s 1987 cost ofS26. 13. Bray. W. C.: Lslimer. W. M.A Course in Conerol Chamisfry.3rd ed.;MaeMillan: New York, 1940. This laboratory text ia hardbound, so you may be able to find it in your local college library. It was described by Nobel Lauresta H. Taube in his 1985 Priestly Medal Address: Taube. H. Chsm.Eng. News 1985.63(18), 40. 14. Hildebrsnd, J. H. Science 1922.55. 355. 15. Schlesingor. H. I. "The Contribution of Laboratory Work to General Education," J. Chem. Educ. 1935.12.524.
Volume 65
Number 9
September 1988
787
