Week Three: 9/23-9/29 - Stoich Test and Intro to Lewis Structures

          This past week, our primary event was our second large test (First to do with stoichiometry) on Wednesday. We used Monday and Tuesday of this week reviewing significant material for the test in class. Following the test, we were introduced to the basics of Lewis structures on Thursday and Friday. This basic information helped us to complete a brief lecture quiz due Sunday night. 

          The week began on Monday with a little review on the concepts we learned throughout the past month regarding stoichiometry. Some on these included Theoretical Yield, Actual Yield, Mass Percent, Limiting Reactants, and Empirical Formulas. We went over a lot of material as a class with whiteboards on Monday while Dr. J assigned us three, multiple-choice, review quizzes online for us to do without a calculator online as homework. These quizzes were fantastic prep for the test and almost completely covered all of the concepts we needed to know on the multiple-choice part of the exam. Given below is a brief lecture covering how to do the math portion of the exam without a calculator. It even hinted a little at the formulas we may have needed to know for the test.

No-Calculator Math Lecture

          The day before the big test, we worked on problems very similar to the quizzes he assigned for us to complete by Tuesday night. This in class review helped me out tremendously especially regarding the problems I was very puzzled on. We mainly focused on reviewing problems that had to do with Masses and the Mole but we eventually got a solid few minutes to review Chemical Equations, Stoichiometry, and Stoichiometric Applications further in depth. Overall, the test had a better outcome than I expected but I still was not particularly satisfied with my final score. I should dedicate more time to reviewing for the exam earlier in the week before the next big test.

          Following the test, we worked all day on Thursday and Friday in table groups on a POGIL activity explaining the basics of Lewis structures and covalent bonds. We stopped periodically throughout the POGIL at various points in which as a class we proceeded to white board and go over the more important answers. Learning the concept of drawing Lewis structures became much easier with the POGIL explaining it in a simple and concise way. The image below makes it very easy to understand what a covalent bond is and also very easily shows us how to draw a Lewis structure.

          Lewis structures have a very basic format and are just as easily formed. It is very important though to remember the rules of the Lewis structures when creating them. The image below briefly gives the two most important rules when making a Lewis structure.

          As you can see, this week mainly consisted of reviewing for the test on stoichiometry but also featured a two day introduction to Lewis structures. My participation in class this week was overall very good. I believe I heavily contributed to everything our group and class did this week. I do not particularly have any questions on what we learned this week, I understood the concepts pretty well. Overall, I am very comfortable with my understanding of what we learned this week. I feel very confident that I know almost all of the information very well. I could still work on mastering stoichiometric problems but overall I feel I am alright where I am regarding those. My only question would be, where do we go from here? 

Week Two 9/16-9/22: Stoichiometry and Empirical Units

         This week, our main focus was on continuing to perfect our knowledge of stoichiometry. We worked through the worksheets of Stoich 3-8 either as a class with white boards or at home using the online lectures to guide us. By the end of the week, we also were introduced to the concepts of Empirical units and molecular formulas. These concepts were presented in class through a college level POGIL which we worked on together in groups and through two worksheets we did for homework.

         
          The beginning of the week started off primarily with review from the week prior, calculating the amount of grams in different substances using the Mole Ratio. As the week progressed, we began to learn newer concepts of stoichiometry such as the limiting reactant and the reactant in access in an equation. This concept was first explained to us using an analogy with car parts in a POGIL. The remaining tires would serve as the excess reactant whereas the one engine provided necessary to build the car served as the limiting reactant. The image below explains the concept in more depth.

          We applied this concept in class when we completed a worksheet dealing with reaction particles in different diagrams. We balanced the chemical equations and then built different molecules based on the reactants given and the products needed. This worksheet at least gave me a better understanding of what limiting and excess reactants really are. Stoich 7 then only strengthened our skills in solving for the limiting reactants in chemical equations with extra practice problems.

          

          From there, we learned a entirely new concept with Theoretical and Actual Yield. We learned that Theoretical Yield has to do with the maximum amount of product possible from the reactants given where Actual Yield has to do with the measured or actual amount of product from the reactants. Calculating the percentage yield, as seen in the formula below, is quite basic and did not take long for me to comprehend.

          Towards the end of the week, we began to learn about the empirical formula, empirical units, and the molecular formula. We were introduced to the concept in class but the first worksheet (Empirical Formulas 1) and corresponding lecture really helped me grasp the concept much better. The lecture for the worksheet can be seen in the link below. Our class then was given a worksheet over the weekend in which we learned how to calculate the molecular formula through an online lecture. 

http://www.screencast.com/t/xLskmyPz

          All in all, this week was almost fully based on learning the new concepts of stoichiometry with a little review here or there complemented by an introduction to the empirical formula. I believe my participation this week was better than last week in terms of contributing to our group's white board answers during our class discussions but I can always strive to be better. I still am slightly confused on how to get the empirical formula when trying to calculate the molecular molar mass but I'm guessing I may just need a bit more practice on those types of problems. Overall, I believe I have a very good understanding of the concepts we learned this week though. 

          

Week One Blog Post

          This week we learned the basics on a few topics such as the Mole, stoichiometry,  and dimensional analysis (or conversions for short). We also dove into our very first lab this week on the relationship between absorbency and the concentration of a liquid. The main focus of this week though was molarity. Molarity tied together each of the basic lessons we learned this week and helped us use each to complete various parts of the lab.
           The week started with two lecture quizzes, one on the mole, one on dimensional analysis. We learned that a mole is basically the total amount of atomic mass of each element in an equation added together. We also learned that the molar mass of each chemical equation is the atomic mass of that equation in grams. The dimensional analysis quiz taught us basic conversions we would need to know for the future like those below.

          We then worked with stoich problems filling out two worksheets by learning the basic concept of the mole ratio. The mole ratio was very easy for me to comprehend because I am much more number-oriented then word-oriented. These equations we dealt with in these worksheets did just that. That same day we also worked on a lecture quiz on Molarity. The main concept from this lecture was that a solution's Molarity(M) = moles of the solute/ liter of the total solution. This concept was a main factor in completing the lab we did the rest of the week. Another huge concept from that lecture was that volume is dependent upon a solution's temperature. We learned that if the temperature of a solution went up, so does the volume, but the molarity of the solution will then decrease. The link below gives a better understanding on this subject.

http://www.screencast.com/t/vhaDPfok3y9





          The last thing we did this week was a lab on the relationship between the concentration of a solution and the amount of transmitted light through the solution. After breaking off into groups, we tested many different dilutions of a liquid called blue #1, finding the absorbency and concentration of each liquid. We then performed the same test on Powerade and G2 samples to determine their absorbency. The data from these experiments led us to create a linear relationship between the concentration of each solution and the amount of transmitted light in each solution. This lab combined all of the things we learned this week and rolled them into one big experiment.

          Overall, my participation in class and other such things have been pretty good this week. Rating my understand of the unit on a scale of 1-10, I would probably be right around a 7.5. I understand most of the material, but some of the conversions and equations still very much confused me. I was mainly confused on the equations in the third lecture quiz and lecture on Concentration Molarity. I think I just need a little more experience dealing with those kinds of equations and I'll be A-Okay. I need to continue to drill into my head the basic principle of molarity as measuring the moles of a solute over the liters of a solution. Besides that, I have no new questions from this week's lessons.

Yo