## Links to download Zoom Lab Videos and PDF files

- Lecture Date: Tuesday, August 24, 2021
Introduction to the laboratory class. An overview of calculators and mathematical problem solving. The worksheet that was presented is titled Math Review for Chem 3 and can be downloaded here.

- Lecture Date: Thursday, August 26, 2021
Today we took a deep look at measurement and uncertainty. We discussed the agreed upon system by which we take measurements and how we interpret measurements. We also went over the system of Significant Figures, though we still need to look at how to use them in calculations.

- Lecture Date: Tuesday, August 31, 2021
Today we started with a quick check-in on significant figures. We then moved into how to use significant figures to estimate the uncertainty in the result of a calculation. We explored the different way that significant figures are applied for multiplication/division versus addition/subtraction. After the break we looked at the Measurement and Density lab exercise that is in Canvas.

- Lecture Date: Tuesday, September 7, 2021
The first half of the session today was on dimensional analysis. This first half was to support the dimensional analysis type problems that you are working on in lecture. We emphasized the three key conversion factors that should be memorized, as well as the SI system of prefixes that change the value of the base units. We then showed how to structure these problems including using a "road map" approach to help guide the problem solving. The second half of the lecture was on the layout of the periodic table, isotopes and an exercise called "Atoms and Elements". We looked at the basic layout of the table in groups (columns) and periods (rows). We discussed the named families and large groupings such as main group, transition metals, and inner transition metals. The structure of the atom was discussed as was the existence of isotopes - elements with the same number of protons, but different numbers of neutrons. Examples of each type of exercise were demonstrated on the worksheet.

- Lecture Date: Tuesday, September 14, 2021
With exams coming up this week in both lecture classes we devoted most of this lecture to review based on Cisco&s review sheet. We covered topics such as sig figs, rounding, scientific notation, pure materials (elements and compounds), mixtures (homogeneous and heterogeneous), chemical changes verses physical changes, and finally dimensional analysis with moles. The mole concept plays nicely into our next assignment in canvas - The Mole Worksheet.

- Lecture Date: Tuesday, September 21, 2021
This was a big lecture day today. Today we did electron configurations. This is one of the most difficult lectures. It is not that the material or skills are that difficult to learn, but the structure that we are trying to describe can be done very formally with quantum numbers and a mathematical description, or with a more intuitive linking of structure to the periodic table. Trying to align the two concepts makes it difficult. Hopefully I have given you a sold foundation on which to complete the Electron Configuration Worksheet. Most of the time was spent on the concept, but towards the end of the lecture we focus specifically on all of the parts of the worksheet and what needs to be done where.

- Lecture Date: Tuesday, September 28, 2021
The topic for today is nomenclature - the system of naming of ions and ionic compounds. We started with the formation of ions and looking at electronic configurations, electronic arrangements, Lewis Dot Structures, and the reasons that elements form ions. From there we introduce ionic compounds and the nomenclature of ionic compounds. The exercise for today is Writing Names and Formulas. This exercise will be completed in Canvas and due next week.

- Lecture Date: Tuesday, October 5, 2021
Today we worked on Lewis Structures and VSEPR theory. We presented two methods to determine the Lewis structures of molecules. We presented the traditional methode with five or six steps, and along with that looked at common bonding pattern method that can often be faster and guide the traditional method. We also took a look at Valence Shell Electron Pair Repulsion Theory (VSEPR). Here we utilize a predictive model that converts the 2D Lewis structure into a 3D model.

- Lecture Date: Tuesday, October 12, 2021
In today's session we started off by reviewing a few problems from the end of the Lewis Structure/VESPR worksheet. From there we launched into a discussion on bond polarity, molecular polarity, and intermolecular atractive forces. There is no assignment to complete for this week. We do not have a worksheet or lab designed to cover this section, but this was an excellent topic to cover to support the lecture material.

I also apologize, but the recording button did not get hit at the beginning of the lecture. As sometimes happens, I get so excited about the questions that I just launch into a discussion of the topic at hand. I didn't realize that I did not hit the record button until about 45 min into the lecture. The good news is that the recording started at the beginning of the new material, leaving only the Lewis structure work unrecorded. The Lewis structure work is in the notes however.

- Lecture Date: Tuesday, October 19, 2021
Today was gas laws day. We took a look at some thought experiments that helped us to develop the relationships between pressure, temperature, moles and volume. We used the relationships to develop an equality that we call the Ideal Gas Law - PV = nRT. After developing the law we showed several calculations using PV = nRT. Towards the end of the session we developed the Combined Gas Law. We were at the end of an example when we ran out of time and my doorbell rang. We'll pick it up from there next week.

- Lecture Date: Tuesday, October 26, 2021
We spent a second day on gas laws today with an experiment called Molar Mass of a Gas. In this experiment we use the gas laws to "measure" the molar mass of a gas. I put "measure" in quotes because every other time we have desired molar mass of a compound we needed the formula and needed to calculate it from the periodic table. Because of the gas law relationship, if we can measure pressure, volume, and temperature, we can then solve for moles. Once we have moles, and mass from using a simple analytical balance, we can find the molar mass of the gas. I know that explaining this experiment isn't nearly as good or as fun as doing it in person, but it is still one of my favorite experiments.

- Lecture Date: Tuesday, November 2, 2021
The consensus was that we should look at balancing chemical reactions today, so that is what we did. I went through the steps/rules that I use for balancing chemical reactions. The basic steps were presented with several examples. We then looked at some special cases, such as needing an odd number of a diatomic element, and balancing double displacement reactions. Many examples of each type of equation was presented.

- Lecture Date: Tuesday, November 9, 2021
Given that both Cisco and Lucas have exams coming up shortly, we took a break from new material in favor of a review day. In this session we go over the major gas law concepts pulling together all of the equations and concepts into one location. WE also took a bigger look at the three major types of stoichiometry questions with examples. For the stoichiometry section we started by building the overall stoichiometry road map. This is the main component of the Chem 3 course. This road map connects all of the major concepts into one useful visual. Hopefully you guys find this helpful!

- Lecture Date: Tuesday, November 16, 2021
Today we took a look at concentrations. We discussed the different units of concentration and what they are used for. We demonstrated the major type of concentration questions from calculating concentration, calculating volume or moles, stoichiometry, and questions involving density and dilution.

- Lecture Date: Tuesday, November 23, 2021
We took a look at titrations today. Titration is the process of using a solution of known concentration as a ruler to measure the concentration of another solution using a chemical reaction of known stoichiometry. In this session I run through the basics of how to conduct a titration and then we do a couple of examples from the Chem 101 homework.

- Lecture Date: Tuesday, November 30, 2021
Our last lab lecture! Today we take a look at Acids and Bases. This is sort of a monster lecture. Seeing as how you were just starting acids and bases we sort of needed to go back to basics and we had a lot of ground to cover. We started with the definitions of acids and bases. From there we looked at how acids and bases dissociate. To discuss the strength of acids and bases we needed to understand electrolytic solutions. We delved into electrolytes and equilibrium constants to understand weak and strong electrolytes. From there we correlated weak electrolyte with weak base and weak acid, and strong electrolyte with strong base and strong acid. From there we needed to look at the reaction quotient and develop a mathematical construct of equilibrium. We then worked from the auto dissociation of water to develop the concept of pH. We then did a good number of examples of pH calculations. And that's a wrap.