Chemistry Learning

My new life as a chem prof

jeff — Mon, 17 Nov 2008 00:50:21 +0000

This post was imported from my personal blog, as I make the transition to having a professional blog.

Teaching is great. It’s lots of work, but rewarding. My Monday/Wednesday schedule right now is: Wake up at 4:30 am; Get to work before 6 am; hopefully have a decent lecture ready for 9:00 am (General Chemistry I); then finish up the lecture for noon (Analytical Chemistry); Panic for the rest of the day about what we’re doing on Friday in Analytical Chemistry Lab; try to take care of some kind of professional development or service task; go home and grade stuff; go to bed. But, Tuesdays, Thursdays and Fridays are much less stressful and more easy-going, so it’s alright.

The students are really great. One of the other new professors described them with a really appropriate word: “earnest.” They are earnest–they work hard, and are really kind and honest, and they understand that going to college is a big deal.

More on those labs for Analytical Chemistry: I’m making them up as I go! I really want the course to be built on what the pedagogy-savvy folks call “inquiry-based learning.” The basic idea is that students get more out of science courses if they’re designing experiments, asking questions, and taking responsibility for their own learning. That makes it interesting to write labs. Rather than spend time writing up an accurate and complete step-by-step cookbook (which would be boring for me and for the students), I spend my time looking for research questions and things we can explore with the scientific tools we have available in Analytical Chemistry. Then I write up an introduction to provide some background/motivation, and a bullet list of goals and questions students should address. In the writeup I make some suggestions of different options they might consider for their experimental design. But, really, most of the guidance is live, in the classroom, in group discussions. The art (which I could use plenty of improvement in) is to guide the conversation without giving people step-by-step instructions. In the end, I’d like the students to be able to design analytical chemistry experiments, carry them out, and analyze the data intelligently (using lots and lots of spreadsheets!). Every day, I have to repeat to myself, “What do I want them to be able to do?” Wifey taught me that line, and it really helps focus the learning goals. Maybe I’ll post some stories from labs we’ve tried. So far, they actually have been working really well!! The only lab that didn’t work was the one lab that I copied from a lab manual. Bah!

Claude, the Lake and the Limestone

jeff — Sat, 29 Mar 2008 01:33:02 +0000

This post was imported from my personal blog, as I make the transition to having a professional blog.

I just gave a class on chemical equilibrium, and one of the big concepts was that although some things don’t look like they’re changing there are probably still a bunch of chemical reactions happening. They just have opposing reactions that balance things out. After a ridiculously fun experiment with some buckets of water, we talked about an example of the first person to suggest chemical equilibrium: Claude Louis Berthollet.

Berthollet, back in 1803, observed sodium carbonate (Na₂CO₃) on the shore of a lake, and thereafter proposed the world’s first simultaneous back-reaction. The “forward” reaction in question was the well known fact that if you reacted Na₂CO₃ with CaCl₂ in water, they would form CaCO₃ solid (limestone) and salt water (NaCl(aq)). Nobody had yet observed chemical reactions to go in the opposite direction like Berthollet just had. Reactions were just thought of as one-way processes. The observation of Na₂CO₃ on the shore of a (very salty) lake led Berthollet to propose that it came from the combination of CaCO₃ and NaCl. So, this begins to form a very new picture of what’s happening in a lake with a bed of limestone. When you or I look at a lake and its bedrock, we see a system that appears static and unchanging. On the molecular level, however, the lake and the limestone are continuously reacting with each-other. There is a constant reaction of limestone dissolving to form calcium cations and carbonate anions, and there is another constant reaction of calcium and carbonate reacting to form limestone. The lake and the limestone, therefore, are not static, unchanging things. They’re interdependent, continuous processes. Which is cool to think about once in a while. Dude.

Now that I’ve had to give a number of teaching talks on different topics, I’ve gotten into a rhythm of including historical information, which turns out to provide a lot of interesting stories and examples. A few years ago, even, this would not have been very feasible unless you had a collection of books on the history of science and a lot of time on your hands. With Wikipedia, though, you can get stories, time lines, drawings, and old photographs in a matter of seconds. And it’s all Creative Commons, so you don’t even have to think twice about the legality of copying an image. That’s what it’s there for! (Though you may technically be required to reference the original work/artist/license in some cases).

Hormone Pollutants Affect Bird Songs

jeff — Wed, 19 Mar 2008 01:52:05 +0000

This post was imported from my personal blog, as I make the transition to having a professional blog.

There’s an interesting news report in Environmental Science & Technology that hormone pollutants can cause birds to sing more complex songs. Where do these hormones come from? We produce them in our bodies, and we take extra hormones through various medications, and then we pee them out. They end up at the sewage treatment plant, where they’re either poured into a river or lake, or in some places they can get spread onto farm fields in solid waste (yes, using our own poo as fertilizer) or treated water (for irrigation). More importantly though, I think, are the loads of hormones we give to dairy cows, beef cattle, swine, chickens, goats, sheep, buffalo, emu, etc. We feed them hormones constantly, and those hormone supplements don’t magically disappear (they do degrade a little, but not completely). They end up coming out the other end.

What Markman and colleagues have found is that when those hormones get sucked up into worms, and then those worms get eaten by songbirds, it can cause problems for songbird populations. The lady birds looking for a babydaddy make their decisions about who to get with based partially on how well the dude can sing. A male songbird who is doing really well physically is able to turn up his hormones a bit and develop more brain capacity for song complexity. The result is that his singing prowess is normally a good indicator of how well-off he is. The study showed that worms tainted with hormones and endocrine-disruptors (hormone-like pollutants) caused male starlings to over-develop their singing skills, and now the female starlings are more likely to chose a loser to mate with, possibly someone she never would have picked if he wasn’t taking hormones. Will songbird couples around the world start having below-average babies? Or are there some ladies out there who care more about other qualities in a mate? Will we start seeing more songbirds in the coming years who don’t put so much trust in songs? (In which case, we may eventually stop calling them songbirds…) Either way, it’s creepy what kind of world you’re paying for when you buy a hamburger.

I’ve refrained from making the “canary in a coal mine” analogy, because screwing up bird populations is bad enough in-and-of itself. But, so far, we’ve noticed birds and fish having trouble with all of our hormones… what’s next?

Finally, a Good Chemistry Blog!

jeff — Tue, 18 Mar 2008 01:53:11 +0000

This post was imported from my personal blog, as I make the transition to having a professional blog.

I was happy to run across this cool chemistry blog called The Culture of Chemistry. The blogger, a physical chemistry professor, is surprisingly engaging and interesting (as opposed to most chemists who attempt to make prose that’s “cool,” but often can come off as boring and irrelevant). She’s very genuine and has a lot of great stories and background information, as well as just the right scientific details to make the posts accurate and informative without getting bogged down. As well as being high quality, the posts are very frequent and regular, which is a big plus (and not something that most academics would want to keep up indefinitely). Yay science!

America’s “fog of permanent confusion”

jeff — Thu, 14 Feb 2008 01:43:40 +0000

Jerry Schnoor is awesome. He just published this editorial in Environmental Science & Technology (the top journal in environmental science and environmental engineering) with some brilliant damnations like Americans don’t realize how far out of whack we are with respect to any measure of sustainability. We are so far off, we don’t know what the questions are.

This type of scientific journalism is fantastic. It seems like at some point half a century ago scientists decided that it was unprofessional to have strong feelings or a personality. I’m glad to see that starting to fade a bit. Research and data analysis, sure, should be unbiased. But that doesn’t mean we shouldn’t be human beings when we’re talking about how academia relates to the reality outside the ivory tower. If US environmental policy is just plain stupid, let’s call it stupid. That’s more meaningful to most people than citing data, because someone else is always going to have a stupid counter-argument with smoke and mirrors to make the data seem irrelevant to the average person.

Which gets me to a second point: scientific literacy. How much would be enough for most people, to make informed political decisions? I don’t know.

Public access chemistry – chemspider

jeff — Fri, 18 Jan 2008 02:02:02 +0000

Chemistry International just featured an article on a free structure-based search engine for looking up any chemical! It’s called chemspider.

The wow-factor for non-chemists: Interactive 3D graphics! Try this: type in the common name of a compound. Maybe pick a complicated pharmaceutical like vancomycin. Under the structure listed in any of the search results, there is a link called “Jmol.” If you click on this link, you will get a java interface displaying a 3D structure (which was computed using a molecular mechanics computational chemistry program). You can rotate the 3D molecule via click-and-drag, and if you right click on it you get a huge menu full of all kinds of different display options. Okay, maybe the graphics aren’t very impressive to today’s youngster who’s on SecondLife and plays Final Fantasy MXXIV, but these are real molecules dude!!

It’s not that there’s anything special about doing this for a single molecule. The wicked awesome part is how extensive and fast their database is, and how versatile the search options are. And, the whole thing is open-access and community maintained.

Learn about ideal gases!

jeff — Mon, 14 Jan 2008 02:05:12 +0000

This post was imported from my personal blog, as I make the transition to having a professional blog.

i just had a fun interview with a teaching talk on the properties of gases, and in the process of preparing i found this wicked awesome applet created by john gelder and michael abraham and hosted at oklahoma state u. the applet shows you a clear, animated representation of molecular motion according to kinetic molecular theory. the representation changes as you change variables like pressure, volume, and temperature. it’s really fun to play with. notice some cool things:

if you decrease the volume, you can visually verify that the molecules are hitting the surface more often. when molecules bounce off of the surface, they exert a force on the surface. we humans in the macromolecular world define this as “pressure.” the pressure increases when you decrease the volume because the gas molecules hit the surface more often.
you can use helium gas, neon gas, or a mixture of the two. the neon atoms are heavier, but they still have the same average kinetic energy (ie temperature), so they travel more slowly.
they’ve included a really helpful document giving examples of inquiry-based activities using the applet.