Reproduclblllty of Evldence
An exceedingly important principle is that of the reproducibility of evidence, a cornerstone of experimental science. Anyone in the worldwide scientific community can demonstrate the properties of water or aspirin or vitamin C. What about Laetrile, the supposed anticancer drug? Ernst Krebs, Sr., patented a substance with the molecular formula ClaHIIN07 .. .- , as Laetrile in 1958 (British uatent no. 788.855). The claim was made that the s"bstance selectively releases cvanide in cancer cells. killina the cancerous arowth. No one has ever been able tomake ~ a e t r i l by e the method described in Krebs' patent. The stuff sold today has the molecular formula C ~ Q H ~ and ~ NisOproperly ~ ~ called amygdalin. Further, i t releases cyanide in the liver and not preferentially in cancer cells. So much for reproducibility. The warning signals of quackery ought to be clear to any c h e m i s t e v e n t o an introductorv chemistrv student. The preceding are but a few examples of applications of chemical urinciules that are imuortant t o all citizens. I am sure you can thfnk of many others. Llterature Cited (1) Hil1.J. W., J. CHZM EDUC.. 58,996 (1981). (2) Hill, J. W., and Jonea. S. M., J. CHEM. EDUC., 62,328 (3) Hiii,J. W., J. CHEM. E~uc.58.996(1981).
(1985).
Everyday Chemistry: A General Education Science Course for Skill Vocations James R. Hicks West Hills Community Callege Coalinga, CA 93210
A 1971 editorial in T H I S JOURNAL, posed the problem of meeting the needs of science for citizens and suggested that "an imuortant asnect of this nroblem centers about the nature, sophistication, and diversity of the over-all science knowledge-base required if an individual is to function effectively in understanding chemistry-centered social problems."' As an experienced teacher. I wonder how much chemistry a broad range of academic and vocational students can be expected to understand? Of the 1.2 million students enrolled in California's community colleges in 1983, less than 3% transferred to fouryearinstituti&. It is reasonable to project asimiliarpattern for community college students in other states. In addirion to providing c h e m i s k courses for a variety of vocational students, there appears to be a need at these schools for chemistry programs oriented toward a lower range of academic achievement levels. Purposs ot Everyday Chemlstry
In 1970, West Hills College instituted Everyday Chemistry, a three-unit nonbaccalaureate course, which has a threefold function within our curriculum; (1)i t fulfills a general education requirement, (2) i t is an educational complement to several vocational and service-oriented nroerams. and (3) i t trains students who desire to work as aides in an industriai chemistry laboratory. This course has a lower academic
'J. CHEM.EDVC., 48.781 (1971). 'Nelson, M.J., and Denny, E.C.. "Nelson-Denny Reading Test." Houghton-Mifflin Company, Boston, 1960. 'Gardner. Eric F., el. al., "Stanford Achievement Test, Numerical Competence Test," Harcourt, Brace 8 World, Inc., New York. 1965.
achievement prerequisite than do our baccalaureate level courses. The traditional theory-oriented approach, which makes profound sense from the scientific view~oint. was not deemed appropriate for this course since, in many cases, students do not have an adesuate backaround to auureciate .. the "conceptual" approach tb science. ' Student Profiles in the Everyday Chemlstry Course
The course is designated for students with reading and arithmetical computing levels a t the 9th grade. Students with algebra or a previous chemistry course are not advised to take this course because I have found that competition from academically experienced students is likely to intimidate those with less academic experience. The 9th-grade level was dictated by a 10-year study of the scores on the Nelson-Denny Reading Test and the Stanford Achievement Test of Numerical Competence given to students with an ACT score of 14 or less (equivalent to an SAT score of 566-606).2.3 Computer analysis of these scores indicated a mean grade level of 9.08. For many reasons, a vast number of high school students plateau intellectually a t the 9th grade level: therefore. if chemistrv is to concern itself with a lareer proportion of the educable population, i t must recognize a need for more communication with those who are not in academic endeavors. In Evervdav Chemistrv. I trv . to .resent chemistrv in a manner that i; interestiniand creates rapport, learning, and a liking for science. l'he murse helps students to understand some of the chemicals that have bkcome significant in their daily lives and to develop a better understanding of their environment. Much of this is accomplished through experimental observations. For example, they use a pH meter to measure the buffer action of asuirin and household bakineu soda. They evaluate the quality of used permanent radiator coolant bv analvsis of its alkalinitv and snecific eravitv (see table).
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Everyday Chemlstry-Laboratory
Program
Unit I: Introduction to the Laboratory 1. Techniques and Methods of Handling Apparatus and Reagents 2. Introduction to Copyrights and Patents Unit 11: Measurement in the Laboratory 3. Learning to Read Metric Scales 4. Measurement of Volume in the Metric System 5. Calibration of Me Volume of a Test Tube 6. Calibration of the Volume of a Tablespwn 7. Weighing: The Measurement of Mass 8. Weighing: The Determination of Zinc on Galvanized Iron 9. Calibration of Volume with a Medicine Dropper 10. The Use of Balances for Weighing Chemicals 11. Density of Liquids 12. Density of a Regular Solid-A Wood or Metal Block 13. Density of Irregular Materials 14. Determination of Bulk Density 15. Calibration of a 50-mL Graduated Cylinder 16. The Measurement and Application of Specific W i l y 17. Graphical Interpretation of Experimental Data 18. The Boiling Temperature of Water and Salt Solutions 19. Boiling and Melting Temperatures of Organic Liquids and Solids Unit Ill: Preparation and Analysis of Common Chemicals 20. Preparation of Alum from Aluminum Cans 21. The Identification ?I Chemical Change 22. ldsntification of Same Common Anions 23. Determination of pH and Butler Action 24. Determination of Acids in Vinegar. Fruit Juices, and me Alkanlinity of Antifreeze Coolant 25. Vitamin C Analysis in Fruit Juices 26. The Analysis of Household Bleaching Agents 27. EOTA Titration for Water Hardness: Calcium In Milk and Soil 26. Water Microbiology 29. Phosphate in Soil
Volume 62
Number 9
Seotember 1985
767
