The activity described for this lesson plan is fun and successfully demonstrates hydrogen bonding by showing how different oils repel water and then can become miscible in water using a variety of soaps or detergents. To really bring out the full value of this activity it is worthwhile converting it into a formal experiment that exemplifies all aspects of a classical experiment. Students can make creative adaptations and write them up in a Science Fair format or as a practice for open ended types of science testing as is found in the State mandated CAP test. It is easy for students to come up with a defineable problem and a hypothesis as a hypothetical answer to the problem. The procedure is simple to describe and the materials are few and safe. As mentioned in the ‘94 plan, the setting up of the data table is critical for success and the experiment lends itself to all manner of kinds of statistical manipulation. Since technique is also critical in this experiment, there is plenty of opportunity to criticaily reflect upon why testing may not work out as expected. The experiment also lends itself to being accompanied by a short theoretical essay, using textbooks as guide, to explain results. Students can take the experiment a step further by applying the experiment to actual situations in the kitchen or household where their results have relevance and discuss environmental consequences or applications of the same. One can test brands of soaps and differences between effectiveness of dish washer detergents.
What began as a fun activity has now turned into a serious exercise in scientific method, mathematics, interpretation, creativity, application and use in commerce, home, environment, and an exercise in challenging chemical theory. It is critical thinkig at its best.
From a learning theory point of view, tne exercise demonstrates how the scientific method is learned by doing it and not by recital in a rote manner during an introductory class in Chemistry. What has questionable abstract curiosity value as presented by dogmatic teachers adlvocating for the superiority of scientific chemistry over alchemy, now in this manner of presentation, turns the scientific method into a useful logical tool linking theory with the everyday world.