Here's a problem for you

When I took over this teaching gig, my predecessor left a fold behind labeled "Diabolical Organic Problems." I love the word "Diabolical" but some may argue that that title is redundant with "Organic."

I have on occasion given my students diabolical problems to hone their skills. Today in preparation for the cumulative final exam, I gave my General Chemistry class the following question:

A 21.0 cm³ piece of dry ice is placed into a sealed 5.0 L container at STP. The dry ice is allowed to sublime while the temperature is held constant at 0°C. The container also contains 12.7 grams of sodium hydroxide. Sodium hydroxide reacts with carbon dioxide to form solid sodium carbonate and liquid water. What will the volume of the dry ice be when the pressure in the container is 2.5 atm? The density of dry ice is 1.5 g/cm³. Assume the volume of the container is 5.0L.

I'm kind of proud of this question as it incorporates several concepts we covered in the first half of the semester. I'll give anyone who answers this 50 extra credit points.

and here we go....

The new school year is nearly upon us. As usual, Summer seems to have been too short and too unproductive. But, I'm ready to go.

During June and much of July, I have little desire to teach. However, when August gets here, I am usually rested enough to consider starting a new school year. When I start working in earnest during the last week of Summer (as I have been for the last few days) I become much more energized and much more excited for the new year to start. Mentally, I'm ready to go. I've got a few things to do before I'm actually ready for class, but my mind is feeling good.

Last year, I wrote a post about the start of the school year. Man, last year I was stressed. The Summer had been very busy with things related to an accreditation visit. This year, I am obviously a lot more relaxed. The only thing pressing on me is my teaching load.

In the world of small, liberal arts colleges during economically challenging times, people are asked to do a lot more. Here's my teaching load this semester:

• General Chemistry (5 credits)
• Organic Chemistry and labs (4 credits)
• Advanced Organic Chemistry (3 credits)
• Intermediate Algebra (3 credits)
• General Biochemistry independent study (4 credits)
• Research mentoring (2 students)

That is a ridiculous load, but it prevents the need to hire an adjunct or to cut classes. I can handle it. It's no worse than being in grad school. But, by November I may feel like this:

My verdict

Relating to my last post.... I have decided to give my student the A-.

I appreciate all of the comments. It was a bit unfair to ask for input based on essentially zero information.

In the end, I needed to consider whether she was an A student despite this technicality. The bulk of her work justifies the A-.

Grades are a tricky thing. For many of us teachers (but obviously not all), grades still mean something. They are a indication of the student's mastery of the material. This could become a very long post, but let me just say, an A in one of my courses means the student has the highest level of competence and mastery of material in that course. I only give As to students that deserve them. Many students don't like that policy.

Finish line in sight

I've got my Biochemistry final to grade (mark), Organic and Biochem labs to grade (mark) and then I am done. I will submit my grades and put this semester behind me... sort of.

******

Units are important. A number means nothing without units. Understanding units is important. Units will also tell you how to do a problem or at least tell you if you set it up correctly. I require all answers to have units on exams and homework. If not, the student will not get full credit.

I had a student, a good student, lose 8 points on the final exam because she forgot units for two answers. No big deal, right? Sadly, this will mean the difference between an B+ or an A– for the course. If she would have gotten 8 more points on the final she would have gotten an A– instead of a B+.

What do you think? Should I give her the A–?


I'll give you my final decision tomorrow.

The end of the year, a life changing event and Longshot

Seven more days until finals week. Not that I'm counting or anything. This time of year is always hectic. Students are frantically trying to finish projects and homework. Professors are frantically trying to cover 5 weeks worth of material in 2 weeks and grade everything.

It's a busy time of year.

Last weekend, I did something that will change my life forever. Well, at least the beer drinking part of my life. I'm not going to tell you what it is. I want to build up some suspense and force myself to make an entry soon.

In the mean time, let me tell you about Longshot beer. The wildly popular homebrew contest held by Samuel Adams brewing produced three wonderful brews once again. Here are my brief reviews:

Double IPA: A wonderfully strong ale with excessive hop flavor. The use of 7 varieties of hops takes your taste buds on a extensive journey. It's just too much. This beer proves that it may indeed be possible to over hop a beer. But, at 9.0% ABV, who cares?

Traditional Bock: A fine example of the bock style. I'm not a huge fan of this style. The flavor is too flat for me, but because of this, it doesn't hide defects very well. This bock is a very good example of a bock.

Cranberry Wit: Only porters get bastardized more than wheat beers. What fruit hasn't been mixed with a wheat beer? Here's another example. It is a good clean beer with a delicate sweet cranberry flavor. The key is that the cranberry doesn't hide the wheat beer. It's a good beer that contrasts nicely with the other two beers.

I need grant ideas

I really want to write a grant proposal, but I don't have any good ideas. Does anybody out there have any great ideas that I could use to put in a grant proposal? I want to get funding from the NIH or NSF so make sure your ideas are in line with the types of projects they fund.

I know I should come up with my own research ideas, but I can't really think of anything that hasn't been done. It's really hard thinking about that stuff. So I need your ideas. Send me your ideas to me soon. Deadlines are approaching.

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Please note: the above note is completely sarcastic. I am not actually looking for research ideas (unless they're really good, of course and can guarantee millions in funding).

My point is this: Parents, stop asking me what your child should do for a science project. Yes, I have millions of ideas, but that doesn't help your child. Yes, some guidance is necessary, but the child must ask the questions.

I will gladly help if your child has a plan and needs assistance designing an experiment to doing an experiment safely. But for crying out loud, don't expect me to tell your child what project to do.

I get asked that a lot, usually from parents. My standard response is "no," but I do offer advice on how to guide the child to discover their own project. Get the child to look around and ask "How?" and then "what if...."

Isn't that what basic research is about and isn't that what a science project should be. It all starts with curiosity. Not all kids are gifted with or nurtured to develop scientific curiosity. They will be the ones that test laundry detergent for the science fair. The scientifically curious ones will take it to a different level.

Just don't ask me what they should do.

'tis the season

We are currently deep in a season many of us in academia both enjoy and despise. It is Letter of Recommendation season.

This is the time of year that students are trying to line up internships, jobs, entry into graduate programs, etc...all sorts of things. If it requires an application, it usually requires a letter of recommendation from someone who knows the applicant and can assess the applicants abilities and temperament.

I get asked to write a lot of these. This year I was asked to write over 20 letters for 8 individuals, including 8 for one person. I'm sure more will roll in as deadlines loom.

Over my years of teaching, I have learned that writing a good letter of recommendation is more challenging than it seems. You must accentuate the positives of the applicant without ignoring the limitations of the student. I tell my students that I will try to write a favorable, yet honest letter. Both of our reputations are on the line. I will not lie or say things that I do not believe. Usually that isn't a problem because most of these students are superb and it is easy to write good things about them.

Sometimes, a letter is easy to write for the wrong reasons. I once had a student who was going to fail my General Chemistry course for the second time ask for a letter of recommendation. I don't remember what he was applying for, but it was a science related endeavor. I told him that any letter I wrote would not be positive given his record in my courses, and I suggested he ask someone else. He insisted that it had to be me. So, I wrote it.

I wrote the letter in the kindest way I could so when I wrote the phrase "I cannot in good faith recommend this person for this position" it didn't seem malicious. It was easy to write and it was short. I doubt he got the position.

On the other side of things, sometimes the student is so talented and qualified that I have to be careful not to sound like I'm practicing for the hyperbole championship.

I recently had one of my best students ever apply to med school. I wrote a two page letter describing how great she was and how she would be the best doctor in the world and she would cure cancer in her first year of med school and solve world hunger and etc... I worked pretty hard to tone down the rhetoric into a more sober and meaningful assessment of her abilities. She got accepted to med school. She starts in August. Cancer will be cured by January and world hunger by July. You're welcome.

A bit of success

I'm feeling less troubled about the organic chemistry problems I encountered recently. I returned the exams today and spent the whole period covering it. I was expecting some weeping and gnashing, but I got a lot of "Oh, now I understand." I also did a fairly in-depth review of what nucleophiles and electrophiles are. I hope it sticks.

I had a bit of success in my Biochemistry class. They are analyzing a dipeptide. The goal is to ID the two amino acids present and the sequence. To ID the N-terminus amino acid they functionalize it with a dinitrophenyl group. Then after hydrolysis under 6M HCl conditions they analyze it by TLC and compare to standards. In years past, we've had modest success for various reasons (usually student error). Today we batted 1.000 (which is really 100%).That made me happy.
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On a related note, for any of you teachers, lab TAs or similar folk, have you ever given the entire class the same unknown? I have. They tend to freak out, but it teaches them to have confidence in their lab technique.

Annoying frustration

As a teacher, I occasionally experience situations that make me wonder if I am the worst teacher ever. There are times when, despite what seem to be my best effort, the point I am trying to make never sinks in. Sometimes after a bit of contemplation, I can figure out what went wrong and do something to correct the situation. But, occasionally there seems to be no solution. It is even more frustrating when the topic is fairly simple.

I recently had one of these frustrating episodes. In my Organic Chemistry class we have been covering substitution and elimination.

***disclaimer: To any non-chemists out there, much of this may not make sense. I'm not going to try to explain what I'm talking about, because based on the response of my students, I'd fail miserably.***

I put the following reactions on the board:

Many of you will recognize this as a classic question posed to organic chemistry students since Alexander first described his ether synthesis. One route will work quite nicely as written, but the other route is fraught with failure. Do you know which is which? If you've read this far, I'm sure you do.

Route A will work. Route B, however, will fail to make the desired product because elimination (to form 2-methylpropene) will predominate.

I put both reactions on the board and asked my students which one will work and which one won't.

Dead silence.

I rephrase the questions to something like, "one of these is a valid strategy and one is not. Which one will work and which one will fail to make the ether?"

More dead silence.

I start asking leading questions, but nothing is clicking. I finally get annoyed and ask, "how many carbons do you need to form a double bond?"

A student timidly answers, "2?" I say, "exactly. Which reaction will undergo successful substitution?"

Nothing.

It went on like this for about 15 minutes. I could not get them to realize that in route A, elimination is impossible. Or, if they did, they could not explain it to me.

This has really annoyed me, because if the entire class fails to figure something out, the most likely culprit is me. Besides, the example I describe above is NOT a difficult concept. I spent about half of a class period describing the difference between the two.

I'll find our tomorrow if it worked. This is the first question on tomorrow's exam.

UPDATE: Only 20% of my students got the answer correct. The others chose B. This is preposterageous!!! They will learn.

"BBA" is for...

Bad Bond Angle!

There are a few things I insist on in Organic Chemistry. One of the big ones is that I expect students to draw realistic bond angles. I am always reminded that this must be very hard for students to do. Even my best students draw impossible bond angles.

Things look like this:

These present teachable moments. I don't bring the sledgehammer down. Just a calm and stern correction. What they have drawn is wrong, and they can learn from their mistakes with proper guidance.

Eventually, when they should know better, I take points away. I once had a student ask me why I took points away. I told her it was because her answer was wrong. She didn't like that. Apparently she felt her ability to put something onto paper was worthy of credit. I had to convince her otherwise.

Midterm exams

It is midterm time. Time for exams.

I'm writing an Organic exam for tomorrow. It covers cycloalkanes and an overview of organic reactions.

Feel free to suggest a question you think I should include on the exam. I'm not opposed to letting other people do my work for me.

Tales of Biochemistry

Some of the comments in my last post got on the subject of Biochemistry courses. The comments reminded me of a couple stories from when I took Biochemistry.

I have had the "pleasure" of taking an undergraduate Biochemistry course not once, not twice, but three times. The latter two were cross listed as graduate courses, so don't go thinking I'm a moron. That should have been obvious long before this post.

I have two stories about my experiences in Biochemistry.

The second time I took it, it was team taught by two professors at a large state university. He was a good teacher, and she was not. One day she was scheduled to teach, but he showed up. The class of about 100 undergrads burst into applause and cheering when they realized he was going to teach and not her. A few class periods when she showed up, the groans and moans were hardly subtle. As a grad student, I didn't think she was that bad. She wasn't good, but not deserving of that treatment. Yet, it was humorous to observe that.

The second story comes from when I took the third time. By this time, I was just going through the motions. I knew most of the stuff and was bored. Sadly, the teacher this time was less interested in accurate chemistry. She would do a lot of things that would make chemists cringe. One day, she decided to deprotonate something with a chloride ion. I don't remember what she was deprotonating, but it doesn't matter. Chloride will never deprotonate anything, especially in an aqueous environment since water is a base about 1,000,000 times stronger than chloride. And that's if you ignore everything else that is even more likely to act as a base. OK, she may have just been trying to simplify things, but when we asked her about it, she would not back down. She tried to convince us that chloride was the base. We decided to not push the issue. The effort was just not worth it.

An analogy is sort of like a....

I'm a big fans of analogies in teaching. I think they can be useful at simplifying complex concepts. They help by putting the general ideas of a concept into more familiar forms. This is gives the student something to grasp and contemplate. The ultimate goal is that the simplified version incubates and eventually provides a foundation for the understanding of the complex concept.

The danger is that the student never gets past the analogy, and the full understanding never develops. So, analogies must be used carefully and judiciously.

With that said, I like to use analogies using kindergarteners (figuratively, not literally).

For example (my apologies to any non-chemists; this is going to get nerdy), I use kindergarteners to explain the stability provided by resonance.

The following carbanion is very unstable and highly reactive because the charge is localized on one carbon.
Whereas, this next molecule, while still quite reactive, is more stable and less reactive because the negative charge is delocalized through the pi system.

The first structure is analogous to being locked in a small room with 20 hyper adn overly energetic kindergarteners. That would be a high stress and uncomfortable situation for everyone involved. What the kindergarteners need is room to run. The second structure is analogous to being in a gymnasium with the same 20 kindergarteners. When the kindergarteners have room to run around, things are a lot less stressful. In other words, kindergarteners are nonbonded electrons.

The year begins

So, Milkshake asked me to tell a little about the start of the school year here at my institution.

That is a great idea. Here it is:

OK, it's not supposed to be this stressful, and it usually isn't. However, the summer for me has been loaded with (as I have alluded to before) the Great Crap related to an impending accreditation review for my school. That's a bit of a big deal if you are in the business of higher education. And, it's an even bigger deal for me because I'm in charge (partially) of getting everything ready. I am really ready for summer vacation fall break winter break.


OK, I'm feeling better. This is very therepeutic tharepeutic theraputic therepuetic STUPID F-ING SPELL CHECK!!! JUST TELL HOW THE F*CK TO SPELL THERAPEUTIC BEFORE I BREAK YOUR FREAKIN SILICON!!!!!

OK, sorry, I'm better now. really. honestly.
So, how does the school year start at my school?

Students move into dorms on Saturday (yesterday).
Girls spend that night figuring out which tank tops to wear during the week.
Boys spend the night trying convince dorm mates that they where the shit in high school.
Matriculation service on Sunday afternoon followed by a campus picnic.
Girls wearing tank tops meet boys who think they were the shit in high school.
Monday is orientation day. All first years report for two hours of blah, blah, blah very useful information.
After that I meet my new advisees, all of whom are probably delusional pre-meds. Oh well, a bit of Organic Chemistry should take care of that.
The rest of the day is spent by me prepping for classes.
On Tuesday, classes officially begin. Lives start to change, for better or for worse.

OK, through most of this post I have been a bit cynical, but that last sentence is true. I've been heavily involved with non-teaching activities related to academic policy during the summer. Right now, I just want to teach. I realize accreditation is important, but (here comes the cynicism again) so much of it comes down to budget. Yes, a school needs to financially stay afloat, but we get paid crap to do what we love to do and what we love to do is why the school is here. This is a place of learning and not just teaching. It's not just about the bottom line.

I am very excited to see my returning students and to meet the new ones. I can't wait to help them learn new things. I can't wait to help them see how cool the molecular level is. I can't wait to torture them with Organic nomenclature teach them about carbon.

I love teaching and I love my job. There are still sooooooooo many non-teaching things that must be done that detract from the teaching, but I still love to go to work.

Thanks Dr. Phil. I feel much better.

What do you want?

So, I've been really bad at posting on this blog. I'm not sure what my problem is. Oh! I know. I've been really busy at work with an impending accreditation review coming up in October.

So much for my summer.

Back in the day when I was pretending to be a premed, I had a med school interview. I was ready to answer all possible questions. So, I was taken aback when the doctor interviewing me asked me, "so, what do you want to know?" That was his first and only question. I didn't expect to be asked to ask questions. Perhaps I was naive. When all was said and done, I went to grad school. However, even before then, I was convinced I wanted to be a chemist. At the time I was just going through the premed motions.

So, I thought I'd ask you, my readers (both of you), what do you want to know?

What do you want to know about brewing beer? About teaching Chemistry? About holding your high school high jump record for 18 years (and running).

I know some things about these areas and will dispense whatever information I have about them free of charge.[1]

So, what do you want to know?

[1] I realize I'm overcharging you, but deal with it!

fin

Done with finals.
Grades turned in.
Desk cleaned off(sort of).
Time to decompress.

Expect normal blogging to continue soon.

Preview:
The fruits of my Beer Journey.
A review of my Kölsch.
Some interesting stuff I recently read about beer and chemistry.

yuck

Dear reader,

Grading sucks.

Your pal,

Eric

Finals week

This blog will be under a finals week induced silence for a few more days. I need to write three finals and then administer and grade them.

However, for the first time in my teaching career, I have finished all of my other grading (lab reports, homework, projects etc...) before finals week. That, my friends, is an accomplishment. Although, the adverse effect of such an effort is that my office is a complete disaster. My desk has enough clean space on it for just my computer. I have piles of papers, books and sundry items all over my desk and office.

It will eventually get cleaned up, but not until after finals week.

Until then, expect very little to nothing from this blog. In others words, everything is normal....

We've all been there

I have a student who has been working on a "research" project for me. The project is to extract a protein called concanavalin A from Jack beans. I use quotes because this isn't a novel area of research by a long shot. My goals for this project were to #1 develop a method of extraction that I could use in my Principles of Biochemistry course and #2 teach my student a variety of laboratory methods.

Concanavalin A (con A) is a lectin from the Jack Bean. A lectin is a protein that binds carbohydrates. In the case of con A, it binds with glucose and mannose but not galactose (or other carbohydrates). It does not have enzymatic activity, and its role in the plant is not clear (as is the case for most lectins).

My student has been working on this project all semester. Briefly, the Jack beans are soaked in pH 4-5 buffer and then blended in a blender. The supernate is removed after centrifugation. It is saturated with ammonium sulfate. The precipitate is collected and dialyzed against 1M NaCl. The protein solution is passed through a sephadex column and the Con A binds with the sephadex. It is displaced by glucose. The solvent used in the sephadex column is 1M NaCl (that's important to remember for this story).

Through trial and error and up the steep learning curve that is undergraduate research, my student eventually got enough sample to the sephadex column part. She loaded the sample onto the column . However, instead of running 1 M NaCl through the column, she used 1 M HCl instead. ugh! There is a big difference between a pH of 7 and a pH of 0. It wasn't good for the protein which, for the most part, appeared to cease to exist intact.

I should point out that she is NOT a bad student or a lab disaster waiting to happen. She is a very good student and one who absolutely knows the difference between NaCl and HCl. But these things happen. Unfortunately for her, that meant the end of her project.

We've all been there. If you've spent anytime in a lab, you've probably made a stupid mistake. I'm not talking about the frustration of dealing with things that don't work. I'm talking about the things that you ruined by a stupid mistake. It happens. The goal is to never repeat it.

No time to brew

I am having one of the busiest semesters of my teaching career. As we approach the end of the semester, things only get busier.

The race analogy is overused and cliché, but....

Teaching is like running a race.

Back in my high school days, I was on the field and track team. I know, it's supposed to be "track and field," but my forte was in jumping events, and I have a greater love for the field events.[1] While jumping was what interested me most, I was also a pretty decent long distance runner. The only problem is that I hated[2] running long distances. I could do it, but I didn't like it. Through incremental apathy I eventually worked my way down from running the mile to the 400 meter "dash."

The 400 meters is an interesting race. It is essentially a sprint. There is no time to coast. Once around the track as fast as you can go. The first 300 meters is tolerable, but the last 100 meters is torture. There is something about rounding that corner, seeing the finish line and feeling the lactic acid[3] in your legs screaming to be oxidized back to pyruvate. It is something that only feels good when you've reached the 402 meter mark.

That's how teaching college feels to me. It starts at a sprint and does not slow down. For most of the semester, the pace is tolerable. But, the last 3 weeks are frenzied with activity and laced with lactate burn. The end is in sight, but to reach it will require some pain.

What I really mean to say is: I want to brew some beer but time and energy are lacking. Maybe I'll just have to carve out a chunk of time to brew and screw the rest.[4]


[1] I still hold my high school's high jump record. Of course, that was about 25 pounds ago.
[2] and hate
[3] actually, lactate.
[4] that is one of the weirdest sentences I have ever written "brew and screw?" What the hell is that?