Clip #1: A coffee-cup calorimeter problem (Exam II F97 #8)

Clip#2: Hess' Law (Exam II F97 #6) (Note: I screwed this problem up during the Help Session so I'd suggest not reviewing the digital clip. I've worked out the problem correctly here, so check it out.

Clip #3: Predicting the products of a reaction and writing the ionic and net ionic equation (Exam II F97 #1d)

Clip #4: What characteristics of an orbital are determined by n, l and m

_{l}? (Exam III F97 #6)Clip #5: Predicting the products of a reaction and writing the ionic and net ionic equation (Exam III F97 #1a)

Clip #6: Frequency, energy drawing an energy level diagram and some discussion of what the word quantized means. (Exam III F97 #4)

Clip #7: Writing electron configurations for Zn, Cr and Cu. (Exam III F97 #8)

Here is the first problem we did from sample test Exam II Question #3.

Here is the second problem we did from sample test Exam IV Question #10.

Here is the third problem we did from sample test Exam IV Question #8.

## There is an audio problem with the last approximately 12 minutes of this video. You can hear me but there is a disgusting background hum that makes listening VERY irritating. Sorry. This was the first time with the new audio feed directly from the wireless mic. It makes the regular audio SO much better, but something funky happened in the last 12 minutes of the tape. Hopefully that problem is solved for the future.

## In Part 1 I do sample problems like PS6.9 (0') and PS6.2 (23' 27") and I discuss PS6.7 (12' 37") and PS6.1 (37') in some detail. I'll have the second half of the Help Session up Wednesday morning. In the 2nd half I discuss PS6.4, PS6.5, PS6.6 and PS6.8. Check the Announcements page.

## We begin the lecture with discussion of molarity, the definition of concentration (5' 54") and the definition of solute and solvent; preparing a solution of a solid and water to obtain a concentration of a particular molarity (12' 40"); preparing a solution by diluting a more concentrated solution (23' 15"); doing a simple solution stoichiometry problem (34' 13"); a second more challenging solution stoichiometry problem (42' 26").

## This part of the video only has two problems. The first is a combustion analysis problem taken from the textbook Problem 3.46 on page 127. We spend about 35 minutes working this problem, but the numbers do not work out as cleanly as they should. I would recommend watching the first 17 minutes or so, after that it goes downhill as we try to determine what the problem is. The second problem we did is like PS4.5. That problem begins at 40' into the tape.

## In the second part of the Help Session we did a sample problem like PS4.10 (1' in to the beginning of the video) and we also talked about PS4.6d (17' 25").

## I've not got the interactivity in this video yet, but there are several sample problems which will help you on PS4. I began talking about limiting reagents at about 12'45" into lecture. The first problem using limiting reagent using the combustion of ethane problem starts at about 20'10"; the second problem with the reaction between calcium and nitrogen starts at about 35'.

## I've not got the interactivity in this video yet, but there are several sample problems which will help you on PS4. Those sample problems are at the following time points; potassium superoxide equation balance and discussion of stoichiometric factors (14'); the first sample problem using the ethane combustion reaction (21'); second sample problem using ethane combustion reaction (25'15"); third sample problem with ethane combustion reaction (28'); sample problem from the reaction of KI and CuCl

_{2}(31'40"); a second problem from the reaction of KI and CuCl_{2}(42'30").

## This digital lecture has no interactivity at the moment. Here are the approximate times (the time provided is the time into the lecture) for the material I covered in class on Monday; my favorite problem (4' 45"), define molar mass (6' 15"), discuss atomic mass (7' 00"), looking at a formula (18' 00"), percentage composition (20' 00"), a second percent composition problem (24' 00"), empirical formula to molecular formula (31' 00"), dealing with ratios (34' 00"), empirical formula problem (40' 30"). I will add the interactivity as quickly as possible.

## This was the first lecture for Chapter 2. I introduced the fundamental particles in an atom, but I did not go into the details of the historical discoveries which lead to our understanding of these particles. We returned to the perodic table to discuss the atomic number, the mass number and the relative weighted-average atomic mass for each element. We consider those elements in the periodic table that liked to lose or gain electrons and talked about how we could determine, just by looking at the periodic table, how many electrons an element would lose or gain. We also introduced isotopes in this lecture. We showed the isotopic symbol and discussed the three isotopes of hydrogen.

## I did a brief review of determining significant figures in a number and proceeded to do a challenging calculation where I kept track of the correct number of significant figure with each operation. I then did four examples of different types of conversion problems. This completed the coverage of the remaining problems on PS1. Self-test #3 has some problems using conversion.

## In this lecture I introduced units of measurement, their importance and discussed base and derived units. We discussed the importance of knowing the symbol for a particular physical quantity's units. We discussed important prefixes you should know for the SI units. There is a table of these in the lecture notes for this lecture. We discussed uncertainty in measurement as an introduction to why we use significant figures. We learned how to determine the number of significant figures in a number and how to assign the correct number of significant figures when doing calculations. Examples of problems are provided inthe lecture notes. There was also a self-test to see if you understood significant figures...with answers. PS1.7 was covered inthis class.

## In this lecture we defined chemistry and introduced the term 'matter'. We discussed the composition of matter and defined atoms and molecules. We discussed the periodic table in terms of symbols and explained the difference between a symbol and a formula for an element. We talked about the phases of the elements and defined mixtures. We looked at several substances and we viewed the reaction between aluminum and bromine. We discussed physical and chemical properties of several chemical substances. I suggested you also review some additional reactions that were on our web site. We also discussed the atomic level diagrams covered in InClass Problem Set #1. The digital video for this lecture has links to each of these specific concepts. This lecture covered problems PS1.1 - PS1.3 as well as ICE1.5

## examples of determining significant figures in a number: from 8/25/00 lecture (2' 40" clip)

## how to determine the number of significant figures in your answer when you are doing calculation: from 8/25/00 lecture (4' 30" clip)