First (Year) Chemistry Lab

Today's highlight of the day is my chemistry lab class. Synthesis and conversion of maleic/fumaric acids from hydrolysis of maleic anhydride, and performing some testing (melting-point comparison, solubility in water) to show that the two geometric isomers do indeed have different properties.

A tidbit about the two:It was known for quite awhile that maleic acid and fumaric acid have the same atoms, same functional groups, but very different properties. It was the eminent chemist van't Hoff who proposed the cause: bond rotation is restricted about a double bond, so maleic acid and fumaric acid actually have different structure and exhibit different properties (e.g. maleic acid is more polar due to the two -OH functional groups on the same side). So, in a sense, this lab recreates the situation in the 19th century when we know that the two compounds have the same names/groups, but behave differently. Well, except we know about hybridization and such, of course. (Before someone complains - yes, molecular orbitals are more accurate than hybridization, but we little first-years don't get to use MOs much.)
Today, we denote this difference about a double bond by adding to the compound's name the prefix cis- (if the two functional groups about the double bond are on the same side of the bond) or trans- (if the two functional groups about the double bond are on diagonally opposite sides of the bond). Well, there's the E/Z notation, but let's just ignore the naming quibbles. Too many possible names for organic compounds...(oh no, this implies that I need to review organic naming. Erk.)

(Information chiefly from Organic Chemistry by Clayden et. al. Apologies for any inaccuracies - feel free to point them out!)

Anyway, sadly, there was no time to take pictures in the lab - everything is a clear solution or a white powder, anyway. No pretty colours. Well, actually, I think the mercury thermometer we get to use is gorgeous, but I digress...

My first impression of the lab class was pretty sad: a large number of people actually bought the manual less than 15 minutes before the class starts. Guess how prepared they were? (It is fortunate that the lab is not difficult: heat, cool, filter; heat, cool, filter...) In an oddly fitting way, a TA "bought" the concentrated HCl required for our lab - also 15 minutes before the lab started.

Fortunately, my lab partner (so far) seems to be a pretty decent sort, and knows what she's doing. My TA seems fairly experienced, as well. Whew! Things started out slow - the maleic acid refused to come out of solution upon cooling - but the fumaric acid was more cooperative and we did finish before the lab instructor kicked us out. The most exciting part of the lab consists of us coughing/trying not to breathe in the HCl fumes as we poured it into the RBF (or praying to the intermolecular forces that be for the maleic acid to precipitate). Oh well, it's still an interesting lab.

As part of the experiment, we needed to perform a melting-point test on the two products. As most people undoubtedly know, this requires filling capillary tubes (sealed at one end) with a few mm of sample. Usually, we do this by (gently) forcing some sample into the top of the tube and "bouncing" the tube down something long and hollow (like glass tubing) to get the sample to the bottom of the capillary tube. Well, in this lab, the lab instructor expects us to obtain the samples by tapping the capillary tubes against the bench. That is all very well...except I broke the capillary tube on my first try. Oops. So, here is my impromptu Glass-Tubing-Substitute-For-MelTemp-Apparatus^TM:

Obviously, the green parts are not used. (Ok, I admit that my invention is not as long as it should be, but I don't have a pen that long...and the capillary tube did bounce. Very nicely.)

Shoutout to lab partner: The melting-point apparatus uses our thermometer as a gauge of temperature. The proper melting point for fumaric acid is 287 ^oC (from CRC Handbook, 85^th edition). The thermometer only goes up to 260^oC. Unless our fumaric acid is unusually impure, we will Not see it melt in time. *Cough* Anyway.

Onto other things:

• I still have to do physics, which is due very soon. Stuck on one question in the assignment. Not to mention the huge pile of practice problems (> 100) I have to work on so that I actually understand what I am doing.
• Currently very much stuck on calculus assignment problems - and there is a tutorial tomorrow. Argh, must finish before tutorial!
• Stats, stats. I have neglected it far too much. Must spend quality time with it. Like this Thursday. But there's orchestra rehearsal...
  
• Now that I did a lab...there exists a lab report to be completed. With luck, this shouldn't take too long.
• Some good news: Done CS assignment 2 (just need to remember to hand it in). Done linear algebra (just need to check it over for typos). Done intermolecular bonding/cubic structures review. Done generic formatting for cover letters.
  
• Some Really bad news: failed resume (75% to pass). It is now fixed to the best of my ability, although it'd be nice if the TA who marked it gave me detailed remarks instead of a generic comment of "there are some good points, but look at the rubric". Waiting nervously for the resume to be marked before job postings go up officially.

Well. Another busy night. Plan: lab report, calculus, statistics, physics, cover letters, in that order, where bold means "I must finish by tonight or else".

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Sudden outburst due to current conversation:
The two sets of sample data are there for you to check your code. If you believe your code is right, you should be confident of the results it produces. Don't ask me to give you the numbers, because I won't. (Yes, I am unkind this way to lazy people.)