Chemistry-Is It Useful? M. W. Moy University of Houston-University
Park, Houston, TX 77004
Is chemistry useful? For what? By whom? These questions are sure to he asked in the typical introductory chemistry course. Students deserve more in the way of answers to these questions than can he offered in the preface, introduction, and/or first chapter of their texts. They should he shown that chemicals and chemistry are intimately involved in the world's economy ( 1 ) and strongly influence our health and lifestyle (2).Perhaps we do not have time to answer all these questions directly. Intelligent use of the news media can, however, inform our students and increase their appreciation of chemistry with a minimal cost in terms of class time. News Media Sources The daily newspapers are filled with chemistry and chemistry-related items. An often overlooked feature is the financial page. The financial page reflects the structure, the functions, and the state of the economy through stock prices in industries such as those producing metals, chemicals, petroleum, pharmaceuticals, textiles, paper, automobiles, and electronics. The dependence of consumer prices on hasic manufacturing processes and raw materials will be more real to our students after they have examined the financial page. The news media-newspapers and popular magazinesprovide an endless source of information on a wide variety of chemical topics. These timely topics can he used to teach and/or reinforce some fundamental chemical concepts. A magazine article on ordinary table salt will serve to illustrate this point. The Salt Story The March 15, 1982 issue of Time magazine contained a story in its medicine section entitled "Salt: A New Villain?" ( 3 ) .The article included arguments that the American public was eating too much salt and that this was injurious to health. Excessive salt intake is known to contribute to hypertension. The article parenthetically mentioned that it is the sodium in salt that is the real culprit in our diets. Little was said ahout other food sources of sodium.
1038
Journal of Chemical Education
We can take advantage of this article to teach chemical principles and show their usefulness. A stoichiometric exercise is a good starting point. Students can be asked to calculate the amount (grams, milligrams, moles, and percentage by weight) of sodium in the food eaten in a given day. They can use the library to find information on the sodium content of foods not listed in the article. One source ( 4 ) gave the salt content of practically all the name brand foods. Sodium chloride can he used to illustrate many principles other than stoichiometry. It can he used as an example of ionic bondine and of the face-centered cubic lattice. The reaction hetween the elements illustrates oxidation-reduction. The similarities of Group IA elements can he shown using sodium as representative of the group. Sodium chloride can he classified hv (1) users such as industry, agriculture, households, medicine, and transportation or (2) usage end products such as cement, ceramics, dyes, foods, glass, etc. Within either one of these categories many reactions and urocesses are involved which can lead to discussions of many fundamental concepts of chemistry. The im~ortanceof sodium chloride as a raw material and as a chemical intermediate can be stressed. For example, sodium chloride is the substance used to produce eleven major chemicals: NazCOn, C12, NaOH, Na(S), NazSO4, C a C h NaNOs, HCI, NaCN, NaHS04, and NaCIO:+ These chemicals in turn serve as starting materials for the manufacturing processes which ultimately yield many consumer products. Returning to our original question, "Does chemistry seem to he useful?", your rlasses should he ahle to respond affirmatively.
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Llterature Cited
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Y . c ~ .h a . (61 Kaufmann. D. W.. "&dium Chloride: The Pmducliun and Pn,pWtieaofSalt and Brine." Reinhdd Puhlirhers, New Yurt. IJ(II1.
