Of Mental Models, Assumptions and Heuristics: The Case of Acids and Acid Strength Item Type text; Electronic Dissertation Authors McClary, LaKeisha Michelle Publisher The University of Arizona. Rights Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author. Download date 25/09/2021 08:23:20 Link to Item http://hdl.handle.net/10150/194008 OF MENTAL MODELS, ASSUMPTIONS AND HEURISTICS: THE CASE OF ACIDS AND ACID STRENGTH by LaKeisha Michelle McClary _________________________ A Dissertation Submitted to the Faculty of the DEPARTMENT OF CHEMISTRY AND BIOCHEMISTRY In Partial Fulfillment of the Requirements For the Degree of DOCTOR OF PHILOSOPHY WITH A MAJOR IN CHEMISTRY In the Graduate College THE UNIVERSITY OF ARIZONA 2 0 1 0 2 THE UNIVERSITY OF ARIZONA GRADUATE COLLEGE As members of the Dissertation Committee, we certify that we have read the dissertation prepared by LaKeisha M. McClary entitled Of Mental Models, Assumptions and Heuristics: The Case of Acids and Acid Strength and recommend that it be accepted as fulfilling the dissertation requirement for the Degree of Doctor of Philosophy _______________________________________________________________________ Date: 09/02/10 Vicente Talanquer _______________________________________________________________________ Date: 09/02/10 Indraneel Ghosh _______________________________________________________________________ Date: 09/02/10 Dominic McGrath _______________________________________________________________________ Date: 09/02/10 Debra Tomanek _______________________________________________________________________ Date: 09/02/10 Kristin Gunckel Final approval and acceptance of this dissertation is contingent upon the candidate‘s submission of the final copies of the dissertation to the Graduate College. I hereby certify that I have read this dissertation prepared under my direction and recommend that it be accepted as fulfilling the dissertation requirement. ________________________________________________ Date: 09/02/10 Dissertation Director: Vicente Talanquer 3 STATEMENT BY AUTHOR This dissertation has been submitted in partial fulfillment of requirements for an advanced degree at the University of Arizona and is deposited in the University Library to be made available to borrowers under rules of the Library. Brief quotations from this dissertation are allowable without special permission, provided that accurate acknowledgment of source is made. Requests for permission for extended quotation from or reproduction of this manuscript in whole or in part may be granted by the author. SIGNED: LaKeisha M. McClary 4 ACKNOWLEDGEMENTS Reaching this stage in my life was not by sheer will alone. Dozens of people have supported me and encouraged me along the road toward my Ph.D., many of whom are Facebook friends who helped me through those days of writing when I just wanted to quit. I thank my mother, Dr. Jennifer Brown Barber, and Shenica Smith for keeping it real; I definitely appreciate the tough love and the perspective. I especially appreciate the comraderie of fellow science education colleagues, particularly Dr. Marilyne Stains, Dr. Sanlyn Buxner, and Athena Ganchorre. These ladies were the iron against whom I sharpened my skills; our deep conversations about science education and higher education helped me develop into a better researcher by exposing me to ideas and areas of research that were quite disparate from my own research focus. I thank Dr. Neal Armstrong, Kimberly Sierra-Cajas, and the Center for Materials and Devices for Information Technology Research for providing me with the opportunity and the funding to work on projects that expanded my areas of expertise beyond my dissertation research. I also thank Dr. Marc Tischler, Dr. Anne Padias, and Cindy Neal for the best teaching assistantship ever, instructor for two sections of BIOC 395B. I also acknowledge my advisor, Dr. Vicente Talanquer, for helping me accomplish my goal of completing a Ph.D. in chemistry. Dr. Talanquer helped me to set some boundaries for my zealousness. The most important lesson he taught me was to be flexible as a qualitative researcher. Finally, I thank the students who volunteered for this study. Without them, I would have no dissertation. 5 TABLE OF CONTENTS LIST OF TABLES .............................................................................................................. 8 LIST OF FIGURES ............................................................................................................ 9 ABSTRACT ...................................................................................................................... 11 CHAPTER 1: THE RATIONALE.................................................................................... 13 Purpose of the Study ..................................................................................................... 13 The Importance of Acidity in Organic Chemistry ........................................................ 13 Relevance of this Dissertation Research ....................................................................... 16 Significance of this Dissertation Research ................................................................... 17 Of Mental Models, Assumptions, and Heuristics: The Case for Acids and Acid Strength ......................................................................................................................... 18 CHAPTER 2: THEORETICAL FRAMEWORK ............................................................. 21 Student Thinking in Science ......................................................................................... 21 Student Reasoning in Science: The use of Cognitive Resources .................................. 25 Our Framework: A Model for How College Students Think and Reason .................... 30 CHAPTER 3: PROJECT DESIGN ................................................................................... 35 Context of the Studies ................................................................................................... 36 Participants .................................................................................................................... 37 Research Instruments .................................................................................................... 37 Data Collection ............................................................................................................. 39 Data Analysis ................................................................................................................ 40 Limitations .................................................................................................................... 41 CHAPTER 4: INTRODUCTION TO ACIDS AND ACID STRENGTH ....................... 44 Scientific Models of Acids............................................................................................ 44 Factors that Affect Acid Strength ................................................................................. 46 Atomic Radius of the Acidic Element ...................................................................... 46 Electronegativity of the Acidic Element ................................................................... 47 Hybridization of the Acidic Element ........................................................................ 48 Inductive Effects ....................................................................................................... 49 Resonance ................................................................................................................. 50 Solvent Effects .......................................................................................................... 51 Expert Student Responses ............................................................................................. 55 Task 1A ..................................................................................................................... 56 Task 1B ..................................................................................................................... 56 Task 2A ..................................................................................................................... 57 Task 2B ..................................................................................................................... 58 Task 3 ........................................................................................................................ 59 Task 4 ........................................................................................................................ 61 Task 5 ........................................................................................................................ 62 Task 6A ..................................................................................................................... 63 6 Task 6B ..................................................................................................................... 64 Task 7 ........................................................................................................................ 65 CHAPTER 5: ORGANIC CHEMISTRY STUDENTS‘ MENTAL MODELS OF ACIDS AND ACID STRENGTH ................................................................................................