Here’s something your lab instructor asked me to post to the site: a study guide for the second lab test.

[Study Guide for CHM 100 Second Lab Test: Spring 2008]

I’ve managed to pick up some sort of intestinal bug, so I will not be on campus tomorrow.

CHM 100: The 9:05 AM lecture is cancelled. I will post the Test 3 problem solutions during the day on Monday, and I will return Test 3 to you during Wednesday’s class.

CHM 111: I’ll pass out a new quiz for you during Wednesday’s class. Remember that the report for the acid/base lab is due on Wednesday!

CHM 110/CT: We wont be doing an experiment on Monday, but I should be back for our Tuesday class.

Check back here later for any further updates.

Due to an illness, I was unable to hold lecture classes on Monday, 2/25/08. Here’s what you need to know before the next class.

CHM 100: We will have an in-class quiz (not a take-home assignment) on writing ionic formulas and naming ionic compounds in Wednesday’s class. Study your notes and chapter 5 in your textbook to prepare. You might also find [this material] helpful.

CHM 111: Have the molecular weight for your unknown in last week’s lab calculated before you come to class. We will share data in class, and your write-up for last week’s experiment will be due on Friday morning.

This doesn’t have much to do with chemistry, but I hope you got a chance to view last night’s eclipse. After the clouds blew away, it was impressive.

If you missed it, you can try again at the end of 2010!

CHM 100 students! Your first test will be Friday, February 1^st!

Test covers

• Chapter 1
• Chapter 2
• Chapter 3: Sections 3.1 – 3.5 (The “matter” half of the chapter)

Test format

• Multiple-choice questions. Expect 20-25 multiple choice questions. These will be answered on Scantron sheets. Some of these may require calculations. This section is will be worth approximately 60 percent of the points on the test.
• Problems/fill-ins. Expect ten or so questions of this type. You should expect some unit conversions here, questions about significant figures, and perhaps some density or drug calculations. You’ll need to show your work on any question that requires a calculation to receive any partial credit. No work, no partial credit!

Study guides

You should be able to do all of the “bullet points” on the Chapter 1-3 study guides. Get the study guides by following the links on the right-hand side of this page, or click the links below.

• [Chapter 1 Study Guide]
• [Chapter 2 Study Guide]
• [Chapter 3 Study Guide] <– You’re only responsible for the “matter” parts of this one!

How to prepare for the test

• Start preparing well in advance of the test! Ideally, you have already been working on the study guides and practice problems. If not, start now. Do not expect to do well on the first test if you don’t start studying until Thursday night!
• Go through the study guides and [class notes] and make sure you can do each “bullet point” on the study guide. Some of these “bullet points” will be simple definitions, while others will require much more practice and work.
• Use the [practice problems on the web], the suggested practice problems on the study guide, and [the quizzes] to practice chapter 2 skills. To simulate the conditions on the test, try practice problems without textbook and notes. Don’t look at your textbook and notes unless you get stuck! When you can work the problems quickly and without resorting to looking in your book and notes, you are prepared.
• Learn your calculator! You will be using your calculator to solve
  problems on the test, and you should be comfortable with the buttons (like the “EE” button) before test day! (You’ve also got to remember to bring your calculator on test day!)

… and as always, if you have any questions, you’re welcome to post them here or drop by the office during [office hours].

We discussed how to determine whether molecules were polar or not based on their shapes. To be polar, a molecule has to

1. have at least one polar bond.
2. be shaped in such a way that all of the molecule’s polar bonds don’t cancel each other out.

Dichloromethane, CH₂Cl₂, might appear to be a nonpolar molecule at first glance. Depending on how we draw the Lewis structure, we might fool ourselves into thinking that the two C-Cl polar bonds in the molecule would cancel each other out. However, that’s not really the case. The chlorine bonds are not arranged in a way that allows them to cancel.

This rendering is arranged in the way we draw the molecule on our paper. The hydrogen and carbon atoms are in the plane of the screen, and the chlorine atoms are in front of and behind the screen. You can see that the molecule has a “chlorine side” and a “hydrogen side”, and thus is polar.

If you can’t see it, this rotated rendering below makes the “sides” more obvious.

I’m on vacation until January 2^nd. I intend to enjoy the time away from school, and I hope you do as well. See you next semester!

It turns out that I wasn’t able to go to work on Monday, either, so the computer has “incomplete” recorded for your grades.

That’s my fault (or more precisely, it’s some bacteria’s fault), and your actual grades will get sent to the registrar’s office when I get back to work. It might take a few days for them to show up in the computer, since I’ll have to send them over on good old-fashioned paper.

Enjoy the break, and don’t work too hard during the first eight weeks!

Update (12/12/07): I am back at work and I’ve submitted your grades. They should show up in WebAdvisor soon.

Update (12/14/07): The grades are now available in WebAdvisor

CHM 100 and CHM 110 students:

I’ve entered your final grades into [WebAdvisor]. You should be able to access them now.

If you have any questions about your grade, or would like to see your final exam or lab exam, please drop by my office sometime next week. Don’t call, since I cannot discussi your grades over the telephone!

Happy holidays!

Just in case you try to come by today (Friday) or Monday morning: I will not be on campus today and possibly Monday due to an illness. I will probably be back on campus by Tuesday.

CHT 284 students: I should have your grades in the computer by Monday.

By now, everyone’s aware that I’ve been out sick the past few days. I’ll be back in class on Wednesday (for CHM 110 and 100) and Thursday (for CHT). We’ll talk about any schedule changes in class.

What you might not know is that while I was gone I updated the software that powers this web site to its latest version. If all went well, you shouldn’t notice many differences in how the site operates; the updates were mainly related to site security. That said, if you notice that the update broke anything – or if you have any other questions – leave a comment on this post.