Archive for the ‘College’ Category

The Pauper Professor’s Orgo Library

Wednesday, December 11th, 2013

chembarkfc_kit_200Well, it looks like I’ve been ignoring the blog again. Sorry about that.

We are in finals week here at SLU, and the end-of-the-semester crunch has definitely crunched me (with a lot of help from lab stuff, two chemistry “business” trips within the last month, and the fact that I will be getting married in two weeks (!).

I’m teaching Organic 1 this semester, and it has consumed an inordinate amount of time. But the experience has also been a lot of fun and a good training ground for figuring out how to run a class efficiently.

Like many orgo teachers, I began the year by insisting to the students that the best way to do well in the class is to work practice problems (and lots of them). When I was a wee lad taking orgo at NYU, I walked uptown to the fantastic Barnes & Noble at 5th and 18th and bought copies of Vollhardt and Streitwieser to supplement the problems in Jones. My weekly routine was to read through the Jones chapter in two nights while also making index cards that cataloged each reaction along the way. The rest of my week would be spent doing all the problems in Jones, then as many in Streitwieser and Vollhardt as I could stomach.

But textbooks aren’t cheap, and I feel icky about asking students to shell out extra money for supplemental problems after they’ve already forked over $260 (!) for the class’s required textbook. Of course, the used-book market is flooded with cheap, old editions of organic textbooks.

Over the course of this semester, I undertook a mini-project that involved scouring half.com for deals and assembling a small library of textbooks and solutions manuals as a resource for my sophomore organic students. The last volume arrived two weeks ago, and now my collection occupies almost an entire bookshelf in my office:

cheap_orgo_textbook_library

There are 16 books there: 8 sets of texts and solutions manuals. Here’s what I paid for each book + manual:

Bruice: $3.43 + $0.75
Carey: $3.26 + $0.75
Heathcock/Kosower/Streitwieser: $1.05 + $1.18
Jones: $0.75 + $0.75
Loudon: $4.07 +$4.12
Smith: $0.00 + $0.00 (this is the one SLU uses)
Vollhardt/Schore: $1.05 + $0.75
Wade: $2.22 + $0.75

Those costs are steals compared to the prices listed on Amazon. The shipping on each item ranged from $1.89 to $3.99 and was always more than the cost of each book. In total, my little collection set me back $74.14. The plan for next semester is to cart them over to the main library where they can be kept on short-circulation reserve. Students can check out the books for a day at a time—long enough to work or copy the problems in a chapter, but not long enough to hog the resource. Anyway, with eight texts as options, I’m hoping the market for orgo practice problems at SLU is now saturated. I should never again hear wailing about there not being enough practice problems available.

Anyway, the final exam for my class is this Friday—the 13th. I expect the only students who will encounter bad luck are those who haven’t been working enough practice problems.

Organic Chemistry Exam Show-and-Tell

Wednesday, November 13th, 2013

ChemBark's Orgo BunnyWhen I was in college, there was a professor who was notorious among the grad students for stopping them to show off his organic chemistry exam questions. Unlucky TAs on their way to the bog would get tied up for what seemed like hours going through drafts of exams in the hallway.

But now I think I know how he felt. There’s a certain degree of satisfaction associated with writing a problem that makes students integrate their knowledge of multiple subjects within a given set of consecutive chapters in whatever textbook you’re using.

Instead of stopping TAs in the hallway at work, I figured I could move the practice into the 21st century by using the blog. I’ll post any gems I’m proud of in this thread. Feel free to share your favorites as well.

To start…

Exam 1, Problem 3-2. (8 points) Draw the most (Brønsted–Lowry) acidic, optically-active isomer of C6H10.

Click here for the answer. The chapters for this exam included acids and bases, isomerism, functional groups, alkanes, and stereochemistry.

Doctor? No.

Wednesday, October 16th, 2013

bracher_office_doorI generally like to be respectful of people. Toward this end, I try my best to address people properly. You’ll find that I’m pretty liberal in using “Dr.” when addressing letters and e-mails, because you never know when someone is going to get upset at being called “Mister”. In contrast, few people seem to get upset at being called a doctor when they are not. When I was applying for faculty positions last year, I am certain I conferred Ph.D. degrees on a multitude of unsuspecting departmental staffers whose job it was to assemble the applicants’ files.

On the flip side, I have a personal aversion to signing anything as “Dr.” I always check “Mr.” when filling out forms, and I cannot bear to end an e-mail with “Dr. Bracher.” As I am now a teacher, this has established a weird dynamic where students address their e-mails to “Dr. Bracher” and I return them by signing “Paul.” I know this has got to weird the students out because I remember fretting over how to address professors when I was in college. Do you call them “Professor”, “Doctor”, or by their first name? I am pretty sure I always opted for “Professor.”

In my undergrad research lab, it was always a big deal for students when the boss started signing his e-mails to you by his first name. It was an unmistakable signal that you had made it and was regarded as a rite of passage in the lab. In contrast, my graduate and postdoc advisors were pretty much known exclusively in the lab by their first names. Of course, the undergrad-professor dynamic is much different from the dynamic with grad students and postdocs, but it’s always interesting to see how these differences manifest themselves.

Some students attempt to solve the e-mail problem by using the non-direct “Hi,” “Hey,” or “Hello there” salutation. Of course, in trying to avoid any awkwardness, this device mostly just draws attention to it. Would you walk up to a professor and address her as “Hey”? Some of my colleagues sign their e-mails to students as “Dr. D” (or similar), which is an interesting compromise between formal and informal. At the same time, it makes me question what I should address these professors when we are in front of students. Can I say “John” (as I normally would), or should I say “Dr. Doe”?

While I don’t especially care what people call me and would never be offended by any of the standard choices, I prefer “Paul”. But after two months in St. Louis, it seems as if I’m going to be “Dr. Bracher” to the vast majority of students. To friends, colleagues, and those online, I will still be “Paul”, while to family at home, I have always been “P.J.” All are fine with me.

Yesterday, I found myself reconsidering whether to sign my e-mails to students as “Dr. Bracher” to make them feel more comfortable. My conclusion was not to change—signing “Dr. Bracher” would probably make me feel just as weird as if they were to address their e-mails to “Paul”. Anyway, the decision of what to call myself has got to be one of the few privileges to which I am entitled in this new job.

–Paul

Review: ChemDraw for iPad

Thursday, August 22nd, 2013

chemdraw_squareA long time ago, the people at Perkin-Elmer gave me a free download of their not-yet-released ChemDraw app for the iPad. The product eventually launched and I never got around to reviewing it because I was tied up with other things.

I did play around some after downloading it, but my big question was always, “Why bother?” That is, why would I bother drawing structures with a bare-bones version of ChemDraw on a tablet when I could just use a souped-up version of the program on my laptop? Drawing structures with your fingers is kind of hard, the screen is limited in size, and you have to e-mail the structures to yourself for use elsewhere. So, at first, I was not impressed.

Fast forward to the second week of July when Tara and I took a trip to St. Louis to pick out an apartment and meet with prospective grad students. I had a free morning one day, so I came to campus early and sat in on an organic class taught by my colleague Mike.

What was one of the things Mike was doing? You guessed it: using ChemDraw for iPad.

I had only thought about the uses of ChemDraw to research chemists, but it’s actually a really neat tool for teaching. First, the iPad can be connected to the projection system in our lecture rooms, so you can jot reactions down on the tablet instead of using chalk. One of the advantages of this approach is that you can save screenshots and post them online afterwards, so students needn’t worry about copying everything from the board.

That’s not a big deal by any means—chalk is fine—but what is much cooler is how the app can be used as a tool for studying stereochemical assignments. There is a feature in the app that automatically labels carbon stereocenters as R or S and alkenes as E or Z. Thus, making a practice problem for yourself is as easy as toggling the setting off, drawing a molecule, trying your hand at making the assignments, then toggling the setting on to check your answers. Very neat:

chemdraw_ipad_stereochem_practice

On top of that, students can draw nice, clean structures to pose questions about reactions and mechanisms to their classmates or teachers. That’s not bad at all for $10, especially when you consider that a single copy of ChemDraw Standard costs $170. (And our textbook costs $240.)

And, of course, there are things for both students and researchers to appreciate. You can use the tablet to draw a structure and have the app spit out its formula, mass, and mass-by-atom percentages. This feature should be handy for students in orgo labs. You can even use these functions to (improperly) handle solvates when you are desperately trying to get your elemental analyses to pass.

If there is one thing that is especially annoying/limiting about the ChemDraw app, it’s that there’s no tool that lets you draw text or formulae directly onto the screen. I’m hoping Perkin-Elmer fixes that in the next version, but overall, it’s worth the $10.

Disclosure: ChemBark was given the application for free (a $9.99 value).

Other reviews: In the Pipeline, Chemjobber, Chemistry World, Andre the Chemist, Macs in Chemistry, Chemistry and Computers

Edited to add (7 Sept 2013): The latest edition adds a bunch of new features, including text boxes (see below).

Lab Entrance Exam

Thursday, May 30th, 2013

ed_baseballcap_150All of a sudden, I’ve started receiving a deluge of e-mail from undergraduate students looking to start research. Given the space limitations, one of my labmates joked that to be fair, I should sponsor a Hunger Games style competition for admission to the lab.

I have never watched or read “The Hunger Games,” but I am somewhat uncomfortable sponsoring any sort of fight to the death. Nonetheless, it is interesting to think of what characteristics you’d like to have in prospective students. Perhaps a proper entrance exam would be more appropriate than mortal combat?

 

Lab Entrance Exam for Undergraduate Students

The lab entrance exam is held on the first Saturday of each month beginning at 6 am. It is broken down into the following subjects. You may use a calculator. Good luck.

Glassblowing: Given a BBQ grill and a 55-gallon drum of sand, construct a vacuum manifold for your fume hood.

Art of Negotiation: Given a p-card loaded with $50, purchase a stirring hot plate, lab jack, variac, and set of heating mantles for your bench. Hot plate must be IKA-brand or better.

Hazardous Waste Disposal: Using qualitative tests from gen chem and orgo lab, determine whether the unlabeled bottle of frothy orange liquid left in our future lab space should be disposed of as aqueous acidic, aqueous basic, halogenated organic, non-halogenated organic, or heavy metals waste. Fill out an appropriate waste label and carefully move the bottle to the waste collection cabinet.

Visual Acuity: From a distance of two meters, determine absorption maxima for the three solutions of chromophores sitting on the bench. Each chromophore has only one peak in the visible spectrum. Bonus: estimate extinction coefficients.

Safety: Within 15 seconds, locate and activate the lab’s eye wash station after donning a blindfold and being spun around twenty times.

Language/Writing: Translate any article in the journal Tetrahedron into English.

Olfactory Acuity: Given a hard copy of our group inventory, open the stockroom fridge for two seconds and report what bottles are leaking. If you haven’t already fallen unconscious, locate them and tighten the lids.

Skepticism: Write a 2000-word letter detailing the experimental deficiencies of any recent paper by an associate editor or advisory board member of Science, Nature, JACS, or Angewandte. If the editor refuses to publish your letter, upload it to Reddit/chemistry.

Endurance: Collect 1000 10-mL fractions of a streaky porphyrin mixture by flash chromatography. Rotavap each to dryness and collect an NMR spectrum for every 20th fraction.

Shuttle Run: Transport eight 20 L drums of methylene chloride from the VWR stockroom to our lab.

Strength: Steal a belt driven vacuum pump from the lab two floors above ours. Do not use our cart—I don’t want it scratched or stained with oil.

Instrumentation: Using a pair of yellow dishwashing gloves, duct tape, a cylinder of carbon dioxide, and anything you can buy at The Container Store for under $100, construct a glove-box suitable for our work simulating the prebiotic atmosphere.

Manual Dexterity: Replace the regulator on a nitrogen cylinder using no tools but your bare hands. Fastest time wins maximum points, but leaks in the system will result in penalties.

_

I’d be happy to take any students who could finish these tasks, even if they were lazy and skipped one or two of them.

 

An Interesting Position at Columbia

Tuesday, May 14th, 2013

I don’t know why I find myself writing so many posts about happenings at Columbia, but I do. And the trend continues, thanks to this ad I found on page 84 of the March 18th edition of Chemical & Engineering News:

 IMG_2756

The ad begins:

THE DEPARTMENT OF CHEMISTRY seeks to appoint an Associate in Discipline beginning July 1, 2013, for our busy undergraduate laboratory programs. This is a full-time special instructional faculty position with multiyear renewals contingent on successful review…

An Associate in Discipline, you say? Great. I can think of a few chemists at Columbia who need to be disciplined (1 2)…