113 - Making the implicit explicit in acid-base instruction

Jodi Davenport, David J Yaron, Michael Karabinos, James Greeno Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, United States; WestEd, Oakland, CA, United States; Department of Instruction and Learning, University of Pittsburgh, Pittsburgh, PA, United States

Chemical equilibrium is a central theme in introductory chemistry and lays the groundwork for acid-base chemistry and other topics. Through studies on expert versus novice problem solving, we have found two important concepts that are left implicit in traditional instruction. One relates to the nature of the progress of reaction variable, Q. The other is a general problem solving strategy that is based on making a clear distinction between majority and minority chemical species. This strategy provides a single approach to any equilibrium problem, including difficult problems in acid-base chemistry. The strategy also focuses student attention on the most important conceptual aspects of the chemistry, such as identifying which species react strongly with one another. Instruction that makes these two concepts explicit will be presented (see http://www.chemcollective.org/equil/), along with studies that show this new strategy leads to a substantial increase in student performance on equilibrium problems.

Monday, August 23, 2010 10:05 AM
Teaching Acid-Base Concepts in General and Organic Chemistry: Current Approaches to Improve Conceptual Understanding and Retention (08:30 AM - 12:15 PM)
Location: Seaport Hotel
Room: Seaport Ballroom A