I recently posted sample exams for CHEM 233. While I think studying from samples can be dangerous since this sometimes encourages students to memorize material rather than learn it, the samples communicate clearly the type, formate and difficulty level of content to be tested. My aim was also to eliminate any disparity between students without samples and those who acquired old exams from classmates who had previously taken 233. My recommendation is to use the sample exams as an evaluation tool after you have studied the material. Review homework questions, assigned reading, course manual readings and prelab lecture notes first, then attempt one of the samples to gauge how well you understand the laboratory concepts and techniques.

Tags: exam, exam 1, studying

The latest spectra are now posted online.  The lidocaine specs look pretty good!!  The final product, lidocaine bisulfate, is not very soluble in CDCl3, which is why some of you may have observed cloudy NMR sample solutions.  The book uses dimethyl sulfoxide (DMSO) for the NMR sample, which is much more polar and better able to dissolve your final product.  We don't have any DMSO currently, so CDCl3 will have to do; Navid's spectra turned out great in CDCl3 anyway.  Just be aware that the chemical shift values (ppm) for each proton signal will be slightly different than those reported in your textbook since chemical shift is solvent dependent.

Tags: NMR, Lidocaine, CDCl3, DMSO

The slides for Friday's (Feb. 15) lecture are now posted. Also, I updated the slides with each student's synthetic target assignments for Project Two. Plan your syntheses so that you will obtain approximately 200 mg of product. Because deciding on a recrystallization solvent system can be time consuming, I will tell you what system works best for the final product: water/ethanol.

Tags: 333, LFER, Hammett

For those students interested in subscribing to this blog as an RSS feed, click on the link entitled "Blog RSS Feed" at the bottom of the sidebar to the left of this page. There is another link above entitled, "RSS." This will simply open the RSS feed for comments only. To be honest, I'm not sure why that's there or how to remove it.

Tags: 233, 333

As many of you have already realized, there is a mistake in the textbook excercise # 5. You should use equation 8.4 (Hooke's Law), not equation 8.5. This question is very similar to 3 & 4. Also, while I'm on the topic of Hooke's law, let me point out that the masses in the equation refer to the mass of a single atom. The most common error is to use molecular weights, rather than atomic masses. You can find atomic mass by dividing the molar mass by Avogadro's number.

Tags: Hooke's, 233, Homework

NMR spectra for CHEM 333 will be acquired by Maria or Brooke each week. These spectra are later processed with iNMR and saved as a pdf file, which will be posted on this website. Each student is responsible for downloading and printing their own spectra each week. If you would like your spectra reprocessed, expanded, etc., send me an email and I'll get right on it. Free versions of iNMR are available (MAC only). If you'd like to upload your own data from the server and process it yourself with iNMR, stop by my office and I'll show you how.

All of your 1H-NMR spectra for benzocaine looked excellent. Great job on your Fischer esterification. We'll discuss the interpretation of 1H-NMR in class on Friday. See you then.

Tags: 333, NMR

Andy Freeman has asked that I let all students know that Friday, February 1 will be the last day that the stockroom will lone out goggles. Reminder: Students without goggles will not be allowed to participate in any laboratory activity.

Tags: goggles, safety, 233, 333

Wow! It's hard to believe we're almost through week 3 already. CHEM 233 students: Be aware that there were a couple mistakes on the prelab lecture transparencies for Lab One. These errors have been corrected in the pdf version, which you can download here.

As most of you have found out, lab one is technically challenging. Your successful completion of the lab on time depends to a large degree on your advance preparation. I strongly encourage you to carefully read the textbook material assigned in the lab manual--especially those sections dealing with new techniques such as boiling point, melting point and IR--before coming to lab. Your familiarity with these topics can potentially reduce your in-lab time significantly.

Tags: 233, notes, Lab1, IR