“Gone” into Solution: Assessing the Effect of Hands-On Activity on Students’ Comprehension of Solubility

Abstract

Solubility is challenging for many general chemistry students, and the interactions of aqueous species are difficult to conceptualize. Derived from the pedagogies of Johnstone, Bloom, and Piaget, our primary research questions probe whether students’ conceptual understandings of solubility could be enhanced by participation in a concept-building, hands-on activity involving manipulatives; whether algorithmic abilities could be strengthened by completion of an equation-writing activity; and whether a multilevel laboratory activity increases students’ ability to transition through Johnstone’s triangle of chemical representations. A control group completed a traditional solubility wet laboratory, while a treatment group laboratory included teacher demonstrations, concept-building, hands-on activities, and a modified version of the traditional laboratory procedure. Pre- and posttests were administered to both groups, and qualitative data were collected from questions answered at the treatment group stations. We observed that treatment group participants, given opportunities to develop submicroscopic conceptual understandings, made gains allowing them to out-perform control group participants in microscopic and macroscopic representations. Analysis of qualitative data produced four main assertions about the way general chemistry students learn solubility. Our findings encourage us to rethink the traditional role of laboratory, which does not focus on conceptual development but rather on development of manipulative skills.