P634: Exploring the roles of energy and entropy in aqueous solubility: An activity-based approach
: Laura P. Eisen, George Washington University, USA
Co-Author: Samantha Glazier and Nadia Marano, St. Lawrence University, USA
Time: 5:15 PM – 6:30 PM
Related Symposium: S33
The generalization “like dissolves like” is traditionally rationalized in terms of energy. However, enthalpy changes alone cannot explain why polar and ionic substances generally dissolve in water and non-polar substances do not. Furthermore, many ionic compounds are not appreciably soluble in water, yet few textbooks explore why some salts dissolve and others do not. Instead, they simply present solubility rules for students to memorize. This presentation describes an inquiry-based module that uses hands-on activities and worksheets to help students understand solubility. For example, students observe what happens when pairs of ionic solutions are mixed, and then use their observations to construct a single solubility rule. This approach encourages them to think about solubility in terms of chemical structure. When they later examine the thermodynamic changes that take place during dissolution, students discover the importance of entropy in the solution process, and recognize what causes some common exceptions to their solubility rule.
P235: Teaching chemistry to prisoners and nonmajors to avoid “Breaking Bad”
: Samantha Glazier, St. Lawrence University, USA
Time: 11:10 AM – 11:30 AM
Room: MAK B1112
Related Symposium: S27
Critical thinking is central to science. As a central learning goal of a liberal arts education, most distribution requirements include a course in the natural sciences. College students generally accept the claim that taking a wide range of courses will help them live meaningful lives. In an introductory chemistry course, students learn how to reason through macroscopic observations with molecular level explanations and how to reach evidence based conclusions. I had the opportunity to teach a chemistry course for non-majors in the model of the national Inside Out program where college students (outside students) take a course with incarcerated persons (inside students) at a correctional facility. My course had seven outside students, ten inside students and one chemistry major who helped develop the curriculum and serve as a teaching assistant as part of his senior year project. The outside students had a range of majors and reasons for their interest in the course. The inside students were men with excellent disciplinary records and a demonstrated commitment to “bettering themselves.” The course focused on fundamental concepts of chemistry with assignments designed to engage broader questions about science and society. For example, the final writing assignment for the nuclear chemistry unit asked students to decide if they would accept an invitation to work on the Manhattan Project. While learning chemistry together, which included puzzling over observations from mini-experiments, an authentic college classroom was created where outside students recognized privilege in their lives and incarcerated men saw themselves as college students.