Value-Related Activities in Introductory Chemistry Charles H. Butterfield Brattleboro Union High School, Brattleboro, VT 05301 Each day's news suggests a growing need to augment introductory chemistry. Drograms with references to chemis. try-based-social controversies. Teachers who work societal issues into their chemistry lessons first must ask themselves, What controversiesare appropriate to my classes? And, how do 1 teach ahout these controversies'? A teacher is confronted bv a vast number of imnortant issues that have highly compiex chemistry underlyidg them. Some teachers solve the problem of selection by avoiding it. They mention a host of relevant issues as they conduct lessons in the fundamental concepts (1).Thus, the unit on nuclear chemistry may be punctuated by passing references to radioactive fallout, nuclear plant accidents, problems relating to the transport and storage of high-level nuclear waste, the anti-nuclear movement, or, more hroadlv. .. the risks and benefits of energy Such a scattershot a p ~ r o a c hmav. pique . . student curiositv. but it does not provide for analysis of the issues or even f i r expressions of opinion. Essentially nonselective, thii approach has one overriding advantage. Many issues can be mentioned without seriously compromising a tightly scheduled syllabus. The assumntion seems to be that bv reneatedlv dronnine" issues into'the laps of alert and in&rested stuients some amount of concern will be generated which the students can then treat in their own way on their own time. In contrast to this broad, shallow approach, there is another way to bring relevant social issues to the attention of chemistry students. The alternative a ~ ~ r o a cDresumes h that a few well-chosen issues discussed some length in class will lead students to become aware of their own value svstems as thev pertain to chemistry-based social controver~ies,~and to develop some ability and inclination to deliberate other issues. Because of the time required to prepare and teach a lesson covering an issue, this approach is necessarily limited to a few such topics per year. Its advantages are that it encourages students to reflect on the causes and effects of science-related social issues and t o define their personal values ( 2 , 3 ) . Selecting issues that will teach chemistry and enhance moral growth a t the same time is not as difficult as it might at first appear. Some topics that have been used in chemistry classes are acid rain damage, carbon dioxide pollution, smog production, use of dioxin-contaminated herbicides, chemical waste disposal, energy and material conservation, high-level nuclear waste storage, and fraud in research. No more than four or five of these issues would be encountered in one year. A small number of carefully selected topics introduced a t appropriate times will stimulate reflection on issues of ethics. The topic, once selected, needs to be worked into a directed classroom activity. The simplest exercises usually consist of (1) some brief background reading, (2) a paper-and-pencil means of reacting to the material, (3) an opportunity to pool reactions, and (4) follow-up discussion. More elaborate activities provide for a research phase and an opportunity to consider the merits of various consequences where there are several alternative solutions to theproblem. Role-playing activities have been developed for a number of chemistrybased social controversies (4). A valuing exercise may take from one to five class sessions to complete, with most such A.
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Presented at the American Chemical Society 12m Northeast Regional Meeting, June 28, 1982, University of Vermont, Burlington, VT.
exercises requiring no more than two class sessions. The following example deals with acid rain and has been designed to fit into a unit on acid arid base reactions. The students receive a two-page summary of the issue. The overall reactions that are proposed for the production of acid rain are included
The summary introduces the term pH and relates pH values t o rate of oxygen production by algae and the rate of decomposition by bacteria (5). The hydronium ion is introduced through brief discussion of two reactions known to occur in acidified soil
These neutralization and equilibrium reactions relate the dissociation of certain soil comr)uunds to the leaching rffcct of acid rain. Resultant heavy metal releases are toxic th some plants and animals. The summary includes examples of damage done by acid rain to building materials. Following some statistics and projections concerning production of oxides of sulfur and nitrogen, the summary concludes with a description of processes for controlling the release of sulfur dioxide gas
CaO + SO2 NazC03 + SO2
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CaSOa(s)'
NazSOds) f CO2
During the brief discussion of these chemical reactions. students iaise question; ahout what should he done to eliminatr or control acid rain, and inevitahlv. w.r s t i m s uf resnonsihilit\r arise. Students are given a list describing some wavs the cost of preventing or repairing acid rain damage might he met. The list includes (1) requiring industry (including automobile manufacturers) to invest in non-polluting devices and processes, (2) government regulation of fuel com~ositionused hv industry a i d private co
