Blog post #3

     This past week consisted mostly of reviewing for our test and learning about Lewis dot diagrams which also tie into ionic and covalent compounds. We took the test on Wednesday and I'm slightly disappointed with my score. I'm happy I was able to achieve a perfect score on the free response section but I'm very frustrated at how poorly I did on the multiple choice. I feel like it's my fault however and I will definitely prepare myself better for the next test. After the test, we began learning about Lewis diagrams. We also learned about how they are used to represent ionic and covalent compounds. Lewis diagrams tie in with ionic and covalent compounds because Lewis diagrams are often used to represent these types of bonds. The Lewis diagrams represent an elements valence electrons. Since the valence electrons are always where the chemistry happens we use Lewis diagrams to show how electrons bond together in covalent and ionic compounds. Some important details about Lewis diagrams are that you must represent and electron on each side of the element before paring them up and you represent a single bond with one line. We learned about all of these things through this moodle: Lewis Diagram Moodle. We also learned about ionic and covalent compounds more in depth through this lecture: http://www.screencast.com/t/e2pjK6Urr2.
     One question I still have of the material we learned this week is, would elements that have valence electrons in the d-shell have to have 10 electrons need 10 electrons instead of eight to meet the "octet" rule? I know that the d-block shells have 10 electrons so I wonder if that affects the Lewis diagrams.
I feel like my participation in last weeks activities was good. In the moodle, my role was to be a reader and I feel like a did a good job in contributing in other aspects of the activity as well. I'd rate my understanding of this material at a eight out of ten. I understand how the Lewis diagrams work but I need some practice with showing bonds. One thing that changed a little through this moodle for me was that I learned that valence electrons are not only the outermost shell. I learned that the valence electrons are all of the electrons that are shown through noble gas configuration.

Blog post #2

     During this past week, we've mostly been focusing on stoichiometry. We also spent a little time learning about empirical formulas. Our main focus however, was definitely stoichiometry. We went over basic stoich problems through various worksheets and also learned some new concepts such as yield. Another new concept we learned about concerning stoichiometry was how to find limiting and excess reactants. Empirical formulas are important because they represent the lowest common ratio. We learned about Empirical formulas in this lecture: Empirical formulas lecture. All three of these ideas go virtually hand in hand. Yield and limiting reactants are very important for finding the accurate real world results of a reaction instead of just the theoretical results. Stoichiometry is also the key behind setting up the ratios in order  to set up an empirical formula. Some important details behind all of these key concepts are that when finding the mass of a product, you must always set up your stoichiometry using the limiting reactant. This is very important because if you don't use the limiting reactant you won't have enough "parts" to complete the molecules in the product. The key detail to yield is that you always need to find the theoretic or actual amount of product produced. Once you have this, you divide the actual amount by the theoretic amount then multiply by 100% in order to get your percentage yield. Finally, you want to make sure your empirical formulas are completely simplified and that you you have no decimals. We did many activities that involved all of these ideas. To introduce us to limiting and excess reactants we did this POGIL: Car parts POGIL. We then moved on to harder sheets throughout the week which made us incorporate all three ideas. We really made sure we understood these ideas by doing like 1000 sheets about them so we know we can be ready for our upcoming test.
     After all these worksheets the only question I have is if its possible to get a perfect or near perfect yield? I was thinking about this because I'm curious to see how close to perfect one could get without any error or uncertainty. My participation this past week has been good as I have done all of the worksheet and contributed to helping my group. Considering how well I was participating, I would rate my understanding of this material pretty high although one thing I should work on more are probably particle drawings. I feel like my ideas this week haven't really changed this week considering we really do anything mind blowing, but I feel like the practice with stoichiometry will pay off in the long run.

Blog Post #1

     

     This past week of chemistry has been pretty intense as we prepared for our first lab of the year. We began the week by learning about the concept of molarity. We learned that molarity was a unit that is used to describe the concentration of a solute in a solution. This is the powerpoint talking about how molarity works:http://www.jfinnan.com/shs/moodle2/mod/resource/view.php?id=50. Another key idea which we learned about this week was stoichiometry.(Stoich lecture)

  Stoichiometry is used to convert units into other units. Some simple examples of this would be converting seconds to hours or miles to kilometers. These two ideas were key in our first lab were we dealt with a lot of concentration and stoichiometry as we calculated the amount of blue #1 one in various solutions and sports drinks. molarity was important because it was the unit we used when finding the concentration of blue #1 in all of the various solutions. We also used stoichiometry when finding the mass in grams of blue #1 in Gatorade and Powerade. Some important details about molarity is that it's unit is moles/liter. This was important in our lab because we were dealing with small amounts of each substance. In order for our molarity measurements to be accurate, we measured our data in micromolars (short for micromolarity) which is 10^-6 molars. Some key details of stoichiometry is that you never bring down a number with your unit during a conversion. You want to bring down the unit so the units will cancel out when you divide but you don't bring down the number because the conversion won't be correct. Our first experiment of the year heavily incorporated the two main ideas of molarity and stoichiometry. Molarity was a key concept in our lab this week as we found the molarity of blue #1 in various solutions in order to find a relationship between molarity and absorbance. Stoichiometry was also key for the final part of this lab where we used the absorbance of powerade to find the mass in grams of blue number #1 in a sample of the powerade. Obviously mass in grams and absorbance are very different unit so a lot of stoichiometry was required. We learned these ideas during the past week through various worksheets, lectures, and lecture quizzes. All of these things were crucial in order for us to understand the material well enough to do the lab. One question I still have about this weeks material is how would using different wavelengths on the colorimeter affect the results? I kind of want to know if the results would be all over the place or still show a linear relationship. My participation this week was good in the learning process of the lab. I believe I did a good job in the learning process because I did all the worksheets and lecture quizzes as well participating fulling during the actual lab. I also feel like a did a good job with the learning process because I feel like I understand the material very well. Although I feel like I understand the material well, I think I could still use some practice with some complex stoichiometry problems. I feel this way because I struggled when we were told to find the mass of blue #1 in a sample of gatorade and powerade. One thing I'm still wondering after the lab is if there is anything else that can effect the absorption of a solution.