Connecting Solubility, Equilibrium, and Periodicity in a Green, Inquiry Experiment for the General Chemistry Laboratory

We present a novel first-year chemistry laboratory experiment that connects solubility, equilibrium, and chemical periodicity concepts. It employs a unique format that asks students to replicate experiments described in different sample lab reports, each lacking some essential information, rather than follow a scripted procedure. This structure is designed, based on research findings on the science of learning, to promote development of students' experimental design and data analysis skills as well as their understanding of the importance and essential qualities of written and verbal communication between scientists. The experiment begins with titration of saturated solutions of magnesium, calcium, and strontium hydroxides followed by the calculation of the solubility product of each compound. Students use their results to determine a periodic trend in the solubility of the group 2 compounds they titrated, apply the trend to predict the solubility of other, toxic group 2 hydroxides, and examine the value of the experiment within the context of a green chemistry philosophy.