Download PDFs of this activity:
Lesson Overview
Students will learn how to identify plastics according to some of their properties and their recycling codes; they will also learn how plastics affect their daily lives.
Student Ability Level and Grouping
This lesson is appropriate for high-school general chemistry students (or even middle-school or ninth-grade physical science students) working in pairs.
Expected Student Background and Skills
Students should already have learned about atoms and molecules; physical properties, especially density; and chemical properties. This activity can be used early in the year as an application of the concept of density to real-world situations, or it can be used later in the year, after bonding between carbon atoms has been discussed, as a way to reinforce the differences in properties between various simple alkanes, alkenes, and derivatives.
Time and Materials Required
Students (or you) will need to gather plastics from around the home before beginning the activities. Actual classroom activities will require two days: one to learn how to separate and identify the plastics and one to identify unknowns.
Consumables
- Plastics samples from everyday objects
- Water
- Isopropyl alcohol (70% diluted to 45%)
- Food coloring
- Corn oil (Mazola oil)
- Acetone
- Water
- Plastic cups for waste plastics
Non-consumables, per lab group
- 4 beakers, 250-mL, or clear plastic disposable tumblers
- 1 beaker, glass, 100-mL, or small clear glass container (for acetone)
- 4 stir rods or plastic spoons (do not use a plastic spoon with the acetone)
- 1 copper wire (#12 or #14 gauge [thicker] is best) approximately 12 inches long
- 1 large cork
- 1 Bunsen burner
- 1 electric hot plate (this can be shared among several lab groups)
- 1 pair of tongs
Learning Objectives
- Students will learn how to use physical and chemical properties to differentiate among and to identify plastics.
- Students will learn about the recycling codes for various plastic resins.
- Students will learn about plastics and the environment and how plastics affect their daily lives.
National Science Education Standards
Science as Inquiry
- Abilities necessary to do scientific inquiry
- Understandings about scientific inquiry
Physical Science
- Structure and properties of matter
- Chemical reactions
Science in Personal and Social Perspectives
- Natural resources
History and Nature of Science
- Historical perspectives
Classroom activities are provided through the generous support of the Biogen Idec Foundation.