CHF Chemistry WebQuest #5 - Teacher's Guide The Great PVC Controversy Back | Home | Student Version

A Chemistry WebQuest

Purpose and Nature of the Activity
Class Time
Resources
Assessment
Useful Teacher Links
Relevant National Science Education Standards

Purpose and Nature of the Activity

The purpose of this activity is to bring students in contact with the sort of dilemma that arises from the downsides of an otherwise beneficial technology and to teach them how it can be difficult to find answers to some problems. The activity is designed to teach students to think critically and to develop the ability to use their own judgment to shape their own opinions when "right" and "wrong" answers are not apparent. It is also designed to train students to use their own judgment when different information sources present conflicting viewpoints and opinions. It is hoped the students will learn that science and technology are important and necessary tools in solving problems like those presented by PVC production and use.

The activity is not meant to be a debate, but rather a cooperative search for viable solutions, with an ear to the viewpoints of many different voices. It is for this reason that we suggest each team have one member to research the positives of PVC and another to research the negatives. Of course, there are many other ways to approach a critical investigation of the PVC issue, and you may choose to implement your own ideas.

In addition to the written reports, you may assign students to make presentations to the class, posters. It is recommended that you have some sort of class discussion of the issue as a conclusion to the activity.

Class Time

Actual class time for this activity can be limited to 2-3 class periods or expanded to suit your needs. Assigning teams and getting the groups started should take approximately one-half period. This should be done well in advance of the discussion day, should you choose to hold a class discussion. The intervening time will be needed for team research. At least a full-class period should be devoted to the discussion.

Resources

Several Web sites are given for the students to begin their investigation, but these are only starting places. It is recommended that you require your students to keep a record of all their sources. This is important when they are using online resources, since the cyberspace is home to many reputable information sources, and many unreliable sources as well. Encourage students to use good judgment in discerning reliable resources from unreliable ones. You may even choose to require students to cite a minimum number of print sources to ensure credibility.

Assessment

In grading the final team reports, use whatever criteria you prefer. We recommend using the five questions listed at the end of the student page as the basis of an assessment rubric. Also we suggest you and evaluate them on how clearly and completely they address each of the questions in their reports.

Useful Teacher Links

Baffled by the Baby Bottle: A Case Study in Chemistry—an activity that can be a compliment or an alternative to The Great PVC Controversy, dealing with the safety of polycarbonate baby bottles. It was created by Michael A. Jeannot, Department of Chemistry, St. Cloud State University, and hosted by the State University of New York at Buffalo.

Chlorine Chemistry Council—don't miss this site, because it offers FREE teaching materials!

Relevant National Science Education Standards

Unifying Concepts and Processes—There are two systems in this activity: the vinyl chloride polymerization system and the PVC-plasticizer systems that are used as flexible plastics. The interaction of system components and the problems that can arise if only one component is problematic are illustrated by the PVC dilemma.

Physical Science—The structure of PVC and the chemical reaction that produces it are included in the introduction to this activity.

Science and Technology—The activity demonstrates the capabilities and the limits of PVC technology and allows the students to explore technological solutions to PVC's drawbacks.

Science in Personal and Social Perspectives—This activity deals with personal and community health, environmental quality, and human-induced hazard issues surrounding PVC and the prospect of using science and technology to meet the challenges these issues pose.