Tuesday, January 27, 2009

Rabbit Hole Day

Happy 177th, Charles Lutwidge Dodgson! O frabjous day! Callooh! Callay!

{via: Warren Ellis}

Please pardon our mess. Your regularly-scheduled, extra-boring science programming will return next week, fortified with more fiber and aged in sawdust for that bland and musty taste your children love.

(Why must Blogger crop my images in a bizarre way? No doubt for its own perverse amusement. Click 'em to see 'em.)







Wednesday, January 21, 2009

I. Melting Point Determination (second and third pages)



That picture. Yes, it's a Mel-temp. I was under the impression that the instruction to sketch any apparatus we used was a license to draw pictures of random laboratory equipment in the margins. To be fair, we did use a Mel-temp. But there was no reason why it needed to be poorly penciled into the notebook.
Notice also that my chicanery knows no bounds: the compound I had was the only yellow powder among the six unknowns, and that meant it had to be m-toluic acid. My melting point data suggested otherwise, but I nonchalantly decided to disregard that discrepancy with the blithe nonchalance of a practiced charlatan. I'm sure there is a big bunsen burner wih my name on it in whatever level of hell Lucifer reserves for fraudulent pre-meds.


Transcription:

Unknown: “D”

Fine, pale yellow powder; slightly acrid odor; insoluble in H2O

  • Placed 0.004g of “D” into capillary tube
  • Placed capillary tube into Mel-temp, beginning at a temperature of 84°C.
  • Raised tem[perature at 70V
  • Melting commenced at 99°C Clear, pale amber liquid
  • Melting was complete at 105°C

Differential: o-anisic acid, dimethyl fumarate, (toluic acid?)*

  • Mixed “D” with o-anisic acid in test tube, and mixed “D” with m-toluic acid in different test tube.
  • Placed 0.006g of each mixture into two capillary tubes, and began heating at 84°C, 70V.
  • The mixture of “D” with o-anisic acid began melting almost instantly at 88°C, and the mixture of “D” with m-toluic acid began at 102°C and completed at 106°C.
  • To confirm, ran a sample of pure m-toluic acid, determining a melting point of 98 - 104°C. This correlates exactly with the experimentally-determined mp of “D.”



*Despite the discrepancy in mp, the physical appearance of “D” was similar only to m-toluic acid, and did not resemble either o-anisic acid or dimethyl fumarate.