BITeS

31 May 2017

Inorganic Chemistry NOT a Trainwreck, 2017!!

Submitted by Adam R. Johnson, Harvey Mudd College

If you recall, I was very concerned back in January that my inorganic chemistry course was going off the rails. Flo has invited me to give a follow-up report on why I don’t think the class was a trainwreck after all.

The goals of my restructuring were twofold. First, I wanted to better support the lab content by moving some of the analytical techniques earlier (Tanabe-Sugano diagrams, magnetic susceptibility and its history, and IR of metal carbonyls, and reduced mass calculations). Second, I wanted to link the lecture and laboratory courses more closely together. Well, the short version is that I was successful in supporting the lab content, but I am not sure that the course was any better linked than before.

Let's start with that second goal. I figured that if students were using course material in the lab, I could then refer between the lab and lecture courses seamlessly. The problem with that plan was that only about half of my lecture students were in the lab, and about one third of my lab students were not in the class. That is probably the topic of another blog post (Flo will be happy to hear that) but the short version is that we restructured our major a few years ago to offer a variety of emphases (such as materials, computational, or environmental) and students no longer take inorganic lecture and lab in lockstep like they used to.

The first goal, however, was met. Students were able to interpret the UV-Vis spectra of Werner complexes and metal acac complexes using the appropriate Tanabe-Sugano diagrams to determine ∆o for their complexes. The Evans method calculations to determine the number of unpaired electrons in the metal acac experiment were more clear for the students. And, since we had done the group theory of metal carbonyl stretches, the students were able to count bands and accurately describe the relative electron density on the metal center in the manganese dppm experiment.

The course felt “wrong,” or “out of order,” for me the entire semester, but that actually kept me fresh and more engaged with the material. I felt a better connection to the class than I have in a while. Because I was deliberately changing the order of presentation, I had to be a lot more organized in the ordering of the material for the students.

What would I change going forward? Well, I am for sure committed to the order of the concepts I used last semester. I was very deliberate and told the students that I was presenting a lot of crystal field theory without any derivation, but we would return after the 3rd week to backfill their knowledge. Had I not kept reminding them, I think it would have been less well-received. I found myself repeating things more than usual. For example, because I presented the results of CFT in order for them to interpret UV-Vis spectra, when I later went back and derived the d-orbital splitting, there was some repetition of material. This happened enough that I ended up having to cut 2-3 days of material out of the course relative to 2 years ago, but I think better organization and management going forward will alleviate that problem.

I guess the main take home message for me is, you can teach concepts “out of order,” if you are deliberate about why you are doing it, and it can lead to a refreshing change of pace for both the students and the instructor.

Comments

Cycling back to a topic can be a very effective pedagogy. It is an example of "spaced repetition," which has been shown to promote effective learning. This also reminded me of Willamette's "spiral currculum" from the 90's: http://willamette.edu/cla/chem/spiral/index.html.