edited b y
J. DUDLEY HERRON Pvrdue University west Lofayetie. ~ n d i ~ n47907 .
Relative Solubility of Some Second Column Compounds-A Computer Simulation Richard K. Putt Mechanicsburg Sr. High School Mechanicsburg, Pa. 17055 My students have had limited success performing the CHEM study experiment "Relative Solubilities of Some Second Column Compounds-Qualitative Analysis" until this year. Performance was significantly improved by the introduction of a computer simulation to allow each lab group a practice run before an unknown solution was assigned. The program is written in Basic for use on an NCR remote terminal. The user selects one of four unknown cations (Ba2+, Sr2+, Ca2+, Mg2+) by entering a whole numher. H e next selects one of four reaeents bv. tvoine.. the reaeent numher. The results arc then typed out, for cvample "1'1'T. FORhlS \\'I'I'H CHHOhlATF: BII'I' I)ISSOI.VES L'I'ON DILUTION" appears when CrOih(aq) is added to SrY+(aq).After four reagents have been added the user is instructed to enter the identity of his unknown. The computer informs the user as to the correctness of his choice. A program list and sample run are available from the author.
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Vocational Chemistry: A High School Option
M. C . Nagel Auon High School Auon, CT 06001 Good students, unwilling students, and those with learning problems have responded with equal enthusiasm to a new. oroiect-oriented course in general chemistrv a t Avon High School. The program provides a broad background of general information in basic topical areas, plus exposure to career opportunities not otherwise presented. T o stimulate interest. each unit onens with a lahoratorv session durine which students hegin to make a p a c t i l a l product like paint, soap, a silvered mirror, or a test-brick of native clay; or they may start to quality test local waters. Each of the projects requires approximately three to five weeks to complete. Continuity of interest is maintained through progressive small achievements in closely-linked lab and class exercises. Skills in experimental procedures are developed, and safety requirements are emphasized in the lab. Classroom discussion of the history of the product and its industrial development add interest and relevance to laboratory procedures. Class time is used to expand and investigate those chemical and physical principles, pertinent to each specific process, which have been introduced empirically by the lahoratory work. Vocabulary building is stressed both in the lab and classroom. New words are de-
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46 1 Journal of Chemical Education
fined, explained, and discussed in terms suitable to the academic level of the class. Accurate record keeping is stressed as a n important aspect of training for lahoratory assistants and technicians in medicine, food processing, the chemical industry, and similar fields. Students are required to prepare final reports on each project. In addition to a standard lab report on procedures, the final report must include an introduction and conclusion. Outside reading on an appropriate aspect of the chemical theory, history, use, or commercial production of the product is required for the introduction. T h e purpose is to acquaint students with the use of available literature as an adjunct to scientific observation and development. The conclusion must include a summary of the results and the student's personal evaluation of the process or product. oroiect The . preparation of paint was chosen as the first . . because it provides a good introduction to a numher of diverse chemical theories, as well as to varied types .. of lahoratory equipment ranging from simple glassware to the centrifuge and fume hood. Basic lab skills were practiced and interest aroused when, after brief orientation, students prepared qualitative samples of yellow and blue pigments during their first lab. In subsequent labs, quantitative samples of yellow, blue, red, and white pigments were prepared. Five weeks after the project began, hoards coated with oilbased paints, mixed and applied by the students, were weatherine in the schoolvard. The paint lilt) cxercikC ~ m p a ~ ny. NOWYork, 1967. Stecho.. Paul C. (Editor). "The Merek Index." (8th Ed.). Merck & Cu.. Inc.. Rahway, N.J.. ISLR.
Volume 53, Number
1. January 1976 I 47
