9/30-10/4

                This week was a lab week in AP Chemistry. We completed our data collection part of the lab on finding the mass of copper in a brass solution. We also worked on a few pogils to further our knowledge on Lewis structures. We completed a pogil on bond order and bond strength, one on resonance and VSEPR theory. We learned a lot of new main ideas from these pogils that will be very important to us.

            The first pogil we worked on was one on bond order and bond strength. Bond order occurs when you need multiple bonds to connect two atoms’ valence electrons together so they can share electrons. A higher bond order will mean that more energy is needed to take apart this bond. A lower bond order means that it will take less energy to take apart the bond. We saw this from working on the pogil on bond orders. This is crucial knowledge for us moving forward and to understand what is going on in the Lewis structures that we build.

            In our next pogil we looked at resonance in Lewis structures. We had already learned what those were about from the lecture quiz that we worked on last week. Resonance is when you can multiple Lewis structures from the bonding of the same atoms based on using different bond orders on different atoms. The best example that we say was the resonance hybrid representation of benzene. You can move around the double bonds on certain C-C bonds around the central atom. The other main concept that we learned from this pogil is that as bond order increases, bond length decreases.

            In our last pogil, we worked on VSEPR theory. This theory shows us the overall shapes of molecules. We completed this pogil by creating a Lewis structure for an atom and then building a balloon model of that atom using the surrounding atoms and unbonded electron pairs as balloons. The central atom was in the center and not needed to be represented by balloons. This pogil helped show us what a compound will really look like when it is bonded.

            This week we also took part in a lab. We completed our data collection part of the lab. Our question which we are testing is what is the relationship between absorbance and concentration of Cu in a brass solution. We tested this by breaking down a brass screw in nitric acid to get it down to only Cu. We then took our absorbency data and will spend next week analyzing this data.

            I thought I had a good grasp of the material that we worked with this week. I didn’t find it too complicated and was able to easily understand the material. My participation in all of our work was 100% except for the day that I was not present. I don’t have any questions about anything we went over this week and I have seen that I still need to work on getting better at preparing for labs better.