9/30-10/6: Lewis Structures and Brass Screw Lab

          This past week was a very interesting one. We began the week with by talking about our second official lab on the amount of mass percent of copper in a brass screw. This discussion gradually took us to our next main concept which was Lewis structures. We spent the majority of the week learning about Lewis structures through various POGIL activities, while also conducting the our lab experiments on the days we were not learning about Lewis structures.

          On Monday we discussed a very difficult reaction in class that would eventually help us find the mass percent of Cu in a brass screw in our lab. We worked in our table groups and white boarded out the formula see below as a class. Coming together at the end, Dr. Finnan finally explained how to solve the reaction and how it was relevant to our next lab. 

8H⁺(aq) + 2NO₃^–(aq) + 3Cu(s) ➝ 2NO(g) + 4H₂O(l) + 3Cu²⁺(aq)

          The next day, we worked on a POGIL regarding the new topic of Lewis Structures with our table members. This POGIL taught us the basics of how to draw valence electrons for groups IA-VIIIA, how to calculate the total number of electrons and valence electrons in a model, and how to actually draw a Lewis structure. The POGIL helped tremendously with the lecture quiz due that night. One very useful resource I liked from the Lecture was the rules on how to create a Lewis structure as seen below.

          The next day, we began our lab to determine the mass percent of copper in a brass screw. We calculated the mass of the screw and the volume of nitric acid that was needed to react with the brass screw in the solution. We then measured the absorbance of the copper solution through a colorimeter to help us find the final mass percent of copper in the brass screw. Following this lab, we worked on two different POGILs on Bond Order and Bond Strength as well as a second one further explaining Lewis structures. These taught us about the different types of bonds in a Lewis structure, what a bond order is, and which bonds were the strongest. These two POGILs along with the powerpoint below helped me a lot when I tried to figure out how to do our second lecture quiz this week. Our last assignment this week was a VSEPR Theory Lab which we did not complete. Although we did not complete it, it helped us get a basic understanding of the lecture quiz due that Sunday.

Covalency Powerpoint

          Overall, I learned a lot of material this week but do not feel completely confident in my ability to make every Lewis structure. Many parts of the POGILs are confusing to me but I feel that I do have a good grasp on the material as a whole. My participation this week was pretty good but again it can always be better. I believe the only thing I need to work on is just looking over the POGILs and lectures until I can fully understand each concept. Who knew making dots and lines could be challenging?