This lab replaces traditional reactions involving chemicals such as copper(II) chloride, 6M hydrochloric acid, potassium hydroxide, and copper sulfate. The goal is to use observations of different types of reactions to discover common threads, ultimately leading to conclusions regarding evidence of chemical reactions. Students will ultimately learn the difference between chemical and physical changes and dispel common misconceptions; i.e. boiling water is not a chemical reaction.
Using the E-Factor formula, students compare the amount of a final product to the amount of waste generated in a chemical process, leading to a discussion of additional green chemistry metrics with respect to chemical reactions.
This lab determines the percent composition of zinc acetate by precipitation of zinc carbonate, replacing a lab that determines the composition of sulfate in alum by precipitation with excess barium sulfate.
Students are challenged to choose and perform the ͚greener͛ of two procedures for the same unknown type of reaction based on the provided toxicity information for reactants and products. The students complete this process for each of the following types of reactions: single displacement, double displacement, composition and decomposition.