1 / 48

Teaching Substitution and Elimination With Real-Life Examples

Teaching Substitution and Elimination With Real-Life Examples. Bob Hanson St. Olaf College, Northfield, MN http://www.stolaf.edu/people/hansonr 20 th Biennial Conference on Chemical Education Indiana University July 29, 2008. Road Map for This Presentation.

Olivia
Download Presentation

Teaching Substitution and Elimination With Real-Life Examples

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Teaching Substitution and Elimination With Real-Life Examples Bob Hanson St. Olaf College, Northfield, MN http://www.stolaf.edu/people/hansonr 20th Biennial Conference on Chemical Education Indiana University July 29, 2008

  2. Road Map for This Presentation • Background: Data-Driven Chemistry • The Course: 1st Semester Organic • The Data: 39 reactions • The Exam: 25 questions • Conclusions

  3. Background: “Data-Driven” Chemistry generate data analyze data extrapolate hypotheses generate hypotheses

  4. Background: “Data-Driven Chemistry” • Start with raw data • Transform the data into meaningful information • Create a working model R. M. Hanson, S. A. Bergman, "Data-Driven Chemistry: Making Molecular Models (Literally) from Electron Diffraction Data”, J. Chem. Educ.1994, 150

  5. Background: focus on analysis analyze data (identify trends) generate data (experimental) generate hypothesis (explain shapes and trends) extrapolate hypothesis (predict shapes)

  6. Application: organic chemistry analyze data (identify trends) generate data (experimental) generate hypothesis (explain reactions) extrapolate hypothesis (predict reactions)

  7. The Course 1st semester of a standard two-semester course 55 students in my section (approx. 120 students total): 39 sophomores 13 juniors 3 seniors Textbook: Paula Bruice, Organic Chemistry, 5th ed.

  8. Focus: substitution and elimination analyze data (identify trends) generate data (experimental) generate hypothesis (explain reactions) extrapolate hypothesis (predict reactions)

  9. Data Sources Ingold, Structure and Mechanism in Organic Chemistry, 2nd Ed., 1969 Compendium of Organic Synthetic Methods, 1971 M: March, Advanced Organic Chemistry, 3rd Ed., 1985 V: Vogel, Textbook of Practical Organic Chemistry, 5th Ed., 1989

  10. The Data

  11. The Data

  12. The Data

  13. The Data

  14. The Data

  15. The Data

  16. The Data

  17. The Data

  18. The Data

  19. The Data

  20. The Exam • 55 minutes • 25 multiple-choice questions • Instructions: • In each case, read each possible answer, use a process of elimination, and circle the BEST answer. If you are having trouble deciding between two answers, briefly explain your final choice. If you do so, use just a few words, just to clue me in to what you are thinking. Do not dwell on any particular problem for an extended period of time. Each question is worth 2 points.

  21. The Exam

  22. The Exam

  23. The Exam

  24. The Exam

  25. The Exam

  26. The Exam

  27. The Exam

  28. The Exam

  29. The Exam

  30. The Exam

  31. The Exam

  32. The Exam

  33. The Exam

  34. The Exam

  35. The Exam

  36. The Exam

  37. The Exam average score: 75% (average exam score for the semester: 73%) three additional questions

  38. The Exam This test was: (a) Easier than I thought it would be. (b) Somewhat harder than I thought it would be. (c) WAY harder than I thought it would be.

  39. The Exam This test was: (a) Easier than I thought it would be. 15 (b) Somewhat harder than I thought it would be. 14 (c) WAY harder than I thought it would be. 1 (d) Maybe a bit harder. 1 (e) About as hard as expected. 16 (f) Not too bad. 1

  40. The Exam I think looking at the data this way… “…is GREAT, I learned a lot!” “…seems to apply to the real world more so than the book.” “…makes for an interesting way of learning about these reactions.” “…really works with the way I think. I liked it a lot!”

  41. The Exam I think looking at the data this way… “…is GREAT, I learned a lot!” “…seems to apply to the real world more so than the book.” “…makes for an interesting way of learning about these reactions.” “…really works with the way I think. I liked it a lot!” “…you can see and think through all parts of the reaction, doesn’t feel as much like memorization and regurgitation of info…you can think through why an answer is right or wrong in comparison with others.”

  42. Conclusions 1/3 • For the most part, students “got it.” • Generally, students did not have trouble with the • definitions of SN1, SN2, E1, and E2. • A significant number of the students were still having • trouble identifying strong and weak bases.

  43. Conclusions 2/3 • Stereochemical concepts and notation were integrated • into 6 of the 25 questions (24%). For these questions, 77% • of the responses were correct. • However, proper axial/equatorial analysis was critical • for 4 of those 6 questions, and for those, the average was • somewhat lower – 68%.

  44. Conclusions 3/3 • Using a data-driven approach can work in organic chemistry. • Students rise to the challenge of guided inquiry. • Substitution and Elimination are still difficult concepts!

  45. Thank you! This presentation is available at http://www.stolaf.edu/depts/chemistry/bh/bcce20

More Related