An Examination of the Teaching and Learning of Resonance in General Chemistry I and Organic Chemistry I Using Variation Theory

Resonance is a fundamental chemistry concept first introduced to students in General Chemistry I, reintroduced in Organic Chemistry I, and then utilized throughout other higher-level chemistry courses. A molecule or ion can be said to exhibit resonance when it can be represented by two or more chemical structures (i.e., Lewis structures) that differ only in their arrangement of electrons. In other words, resonance represents the electronic structure of a molecule or ion when a single Lewis structure does not adequately depict the true distribution of electrons. The molecule or ion is best represented as a combination of all of the structures and is called the resonance hybrid. Resonance is a tool that practicing organic chemists use to better understand the electronic structure of molecules or ions and to make predictions about molecular behavior (e.g., stability, reactivity, etc.). Therefore, because resonance is a useful tool that helps scientists understand and predict chemical phenomena, it is important for chemistry students to understand and practice using it. The current educational research shows that General Chemistry I and Organic Chemistry I students have difficulties understanding resonance. Unfortunately, little is specifically known about the possible origins of these challenges and how instruction might influence students' understandings of resonance. These challenges can potentially impact students' success in their chemistry courses, as developing a foundational understanding of resonance is essential to students' understanding of other higher-level chemistry concepts. Thus, the overarching goal of this study, which was guided by variation theory, is to investigate the teaching and learning of resonance from three different perspectives (instructor, classroom, and student perspectives) in the courses it is first introduced, General Chemistry I and Organic Chemistry I. The following three research questions (RQ) were addressed: (RQ1) What do General Chemistry I and Organic Chemistry I instructors intend for their students to understand about resonance? (RQ2) What is possible for General Chemistry I and Organic Chemistry I students to understand about resonance in General Chemistry I and Organic Chemistry I classrooms based on the information presented to them in their classes? (RQ3) What do General Chemistry I and Organic Chemistry I students understand about resonance in General Chemistry I and Organic Chemistry I classrooms after learning about it in their General Chemistry I and Organic Chemistry I classrooms? By answering these three research questions, (1) I identified eleven features of resonance that instructors believe to be critical for their students to understand about resonance (via instructor interviews), (2) I identified how/if these eleven features of resonance are made available for students to learn about in their classrooms (via classroom observations), and (3) I identified what students understand about each of the eleven features of resonance (via student interviews). These findings were then compared to draw overarching results. For example, by comparing the results from RQ1 and RQ3, I identified differences in what instructors intended for students to understand about resonance versus what students actually came to understand about resonance. Each of these comparisons is discussed in the chapters of this dissertation. Overall, I found that while instructors in this study believed a conceptual understanding of resonance was important, they tended to teach and assess students in a way that prioritized their operational understanding of resonance. For example, instead of focusing on the underlying concepts of resonance, such as the resonance hybrid, while teaching students about resonance, the instructors tended to focus on the rules and processes associated with drawing resonance structures. Consequently, many of the students in this study also tended to emphasize an operational understanding of resonance and often lacked a conceptual understanding of resonance, expressing misconceptions while discussing it. Based on the findings presented herein, recommendations are discussed to improve the teaching practices and instructional materials related to resonance, potentially resulting in more students coming to a meaningful understanding of resonance. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]