Last year's first exam will give you an idea of what kind of exam to expect next Wednesday. There will be differences: we have not covered functional group names this year (Question 1), but we spent more time on Lewis structures and resonance, and I hope (probably in vain) to touch very briefly on atoms on Monday (Section V of Quantum Mechanics). In general the exam is designed to spend time proportional to the time spent in lectures. We will soon be announcing review sessions for the exam. I will lead one on Monday evening.

 A number of former Chem 125 students have enjoyed volunteering with DEMOS, an undergraduate organization that does science demonstrations in New Haven elementary schools. (In fact a freshman founded DEMOS in 1986, while he was taking Chem 125.) They are having an organizational meeting on Wednesday Sept. 20, 2000, at 9:30pm in LC 317. The Coordinator is Ruma Rajbhandari. Click here to visit the DEMOS website.

For class on Wednesday you should begin to read Sections I-IV of the QMech web page.
This stuff is not as difficult as it is unfamiliar. But it is very unfamiliar and counterintuitive, so you need as much exposure as you can get as soon as possible. My guess is at the beginning you will not really understand just from the reading, but it will help you get the most out of the three lectures and the problem set before the first exam if you read it first (and repeatedly).
The quantum mechanical problem set for Monday is demanding. It requires using a Mac computer program that will be demonstrated Wednesday and Thursday evening at the Phelps Cluster. You can download the program "Erwin Meets Goldilocks" (Erwin.hqx under Materials under Chem 125 at classes.yale.edu).
Even if you don't have a Mac you will want to download the Erwin2000Instructions.doc from the same site. This Microsoft Word document contains both instructions for using Erwin and the problem set. Unless you are able, like Josh Dunn last year and Srini Viswanathan this year but unlike me, to use a Macintosh emulator on your PC (Click here for Srini's Instructions), you will find it easier to locate a Mac on which to run the program. Click here for detailed instructions for launching Erwin on a Mac in a cluster.

The spring syllabus should be on-line soon, but for the meantime you may need to be reminded of the Spring exam dates:

Instructions for using MacSpartan to really see the form of MOs.

Valence MOs of some molecules with functional groups HOMO/LUMOs.(HF, CH₃F, H₂C=O, LUMO analogies (HF, CH₃F, C₂H₅F)).

XH₃ Hybridization and Structure. Theory and experimental evidence from spectroscopy.

Understanding the role of Overlap and Energy Match in bonding, from the perspective of the tunnelling proton in an harmonic double minimum. A modified version of the lecture handout.

Overlap of pure and hybrid carbon orbitals at various distances : Graph and Explanation.

Understanding the covalent bond in H₂. How good is the MO = <2^-1/2 (1s_A + 1s_B) idea?

Here is the answer key for the first hour exam. If after looking it over, you have questions about the substance of the answer, or about how your exam was graded, speak first to the individual who graded it and then to Dr. McBride. Questions 1-4 were graded by Mr. Sche; 5,8,10 by Dr. McBride; 6,7,9 by Mr. Ostrovsky.

Preliminary reading on Quantum Mechanics This is duplicated in the more comprehensive document coming later, but it would be very helpful for you to read this before the Thursday demonstration (7:30-9:30 Phelps Gate Cluster, more or less continuous showing) and before the Wednesday lecture.

Click here to download Erwin.zip containing the Macintosh program "Erwin Meets Goldilocks" and the Problem Set for Monday, Sept. 18 (as a Microsoft Word file). Let me know if you have difficulty. Josh Dunn has figured out how to run Erwin on a PC.

One of the most persisten themes of advice from your predecessors in Chem 125 is that it is crucial to work with others in the course. To help you find others to work with, here is a CLASS LIST, sorted by phone number, which in general denotes proximity. (This list is accessible only from IP addresses within the yale.edu domain)

Others are involved in SMArT which helps students in New Haven middle schools. They are meeting Thursday, Sept. 9 at 7PM in the Davenport Common Room. Here is the SMArT website.

The first subject of the course is how we know about the existence of atoms, molecules, bonds. One topic (in honor of the Kansas Board of Education and the Millennium) will be the role of authority in science. If you wish to read to get a head start you can preview the following, which will be assigned as reading at the first lecture: