Students investigate several variables that affect this chemical reaction. Scientific Inquiry Students identify questions that can be answered through scientific investigations. They discuss the types of reactions or changes in volume that occur when two substances such as baking soda and vinegar are mixed. In an extension, students design an experiment to test whether or not polyurethane is a good insulator.
Students observe or conduct an investigation in making polymer foam.
Students use evidence collected during the investigation to explain why the mass of the polyurethane foam is less than the mass of the two starting liquids. Students may be asked to use mathematics to graph results from an extension testing insulation qualities of polyurethane. If the graph of time versus temperature is fairly flat, then students may conclude that polyurethane is a good insulator. Students mix two liquids together and observe a chemical reaction which causes a color change, an increase in temperature. The heat from the reaction causes the blowing agent in the mixture to vaporize and results in the foam's growth to 30 times its original volume.