Blog Post #9

    Calorimetry excersises), and an online activity to introduce us to entropy. We came to understand these ideas by practicing multiple problems and going over them together at the front of the class.
 This past week of chemistry has been quite intense and difficult. Some of the main ideas which we covered where entropy and calculating changes in entropy. We also briefly talked about whether reactions where thermodynamically favored or unflavored using the equation for Gibbs free energy. We learned about how entropy is the ability for molecules to occupy different spaces in different arrangements. Thermodynamics basically defines whether a reaction needs help from it's surroundings in order to occur. These topics are connected because both are used to describe reactions and their characteristics. Entropy will always change when a substance changes states  and often a change in state is either thermodynamically favored or unfavored. Some important details about these two topics are that entropy increases as heat is put into a system because the atoms go  faster and therefore can form more arrangements. Some important details about thermodynamics are that a reaction is thermodynamically favored when it doesn't require assistance from it's surroundings in order to occur. Also you can determine whether a reaction will be favored or unfavored by using Gibbs free energy. To practice all of these topics, we did multiple lecture quizzes, worksheets (
     Some questions I still have are mostly about how to calculate various things. I feel like we've learned about a hundred equations and I really need to practice  knowing when to use them. I feel like my participation this week has been decent. I've done all of the the work assigned but I feel like I just haven't quite absorbed the information as well as I could have. I also wanted to get more lecture quizzes done a day early but I just got lazy. I'd rate my understanding of this week's material at about a six. I feel like I have a basic understanding of what's going on but I definitely need more practice and I'm fairly scared for next week's test. I still need to work on calculating enthalpy and entropy in calorimeter situations. Some ideas that have changed for me is that when heat goes into a system, the temperature of the system actually goes down. I'd never actually thought of it like that before this past unit.

Blog Post #8

 

     This past week in chemistry has certainly been a busy one. Some main ideas that we focused on were inter molecular forces and how they effected different characteristics in ionic compounds. The most important inter molecular forces are London Dispersion Forces (LDF), dipole-dipole, and hydrogen bonding. Although there are a couple other important ones, these are the most important. These inter  molecular forces effect multiple characteristics of ions, one of these is boiling point. The general rule for boiling point is the bigger the ion, the higher the boiling point. This is due to the fact that there are more electrons in bigger ions. When there are more electrons the ion becomes more polarizable which leads to stronger LDF's which in turn leads to a higher boiling point. Some important details about inter molecular forces are that they are much weaker than covalent bonds and hydrogen bonding is the strongest of all inter molecular forces. We did multiple POGIL's to understand all of these activities. The most helpful was probably the one with the Femto beaker and all of the magnetic models ( POGIL on IMF's).
    I feel like I understand everything we went over this week very well and therefore don't really have any questions. My participation this week was very good. I feel like I was a very productive group member as I helped and participated in each of the activities. I would definitely say I understood everything form this past week very well. I found all of the activities relatively easy and haven't encountered too many problems. One thing I could maybe work on is explaining higher boiling points better. I understand it but I should work on explaining it better. One thing that has changed my perception is that larger ions have higher melting points.  Before this I assumed smaller ions had higher melting points because they were more tightly bonded.

Blog Post #7

   

This past week has been very interesting in class. We didn't really  go over a lot of big ideas due to the fact that we had a test and mole day was the day after. Despite all of these events however, we did begin to cover some key ideas about metals. We began to learn about how metals are malleable and ductile and are also surrounded by a sea of electrons. We also had a blast in class on mole day. The cookies were very good and complimented the hot chocolate well. Despite this we also learned and wrote an essay on the chemistry behind paint balls. Metal's property of having a sea of electrons is  what allows them to be ductile and malleable. This is because since the electrons are basically free flowing, the atoms can slide by each other thus changing the shape of the object. Some important details about this is that metals can become alloys which can change metals properties. We did a couple of POGIL's this week regarding the melting point of molecules and ionic bonds. We also watched a lecture on medals (Metals) which prepared us for our lecture quiz. 

     I still have some questions about determining the melting points of specific molecule. I understand that the charge is more important than the size but when does the size overcome the charge? My participation this week could have been a little better. I feel like I could have finished both POGIL's but I fully completed one. (I  blame Nishant). I think I have understood the material pretty well this week but I'll need to review melting point more. I found it pretty interesting how alloys of metals are so drastically different form the metals themselves. One example of this is brass which is an alloy of tin and copper.

Blog Post #6

      WebMO lab report. This lab was very important because it helps to prepare for our test. Some very important details about this lab were the shape and polarity of molecules. Shape was very important and we learned that it is determined by the number of paired and unpaired electron clouds. Polarity is also important because although the atoms in the molecules are polar, they can sometimes cancel each other out making the molecule not polar. The shape of the molecule ties in to this because often times the shape can determine if the atoms in the molecule can cancel each other out.
In this past week we learned lots o' stuff. Some of the things we learned were VSEPR, polarity, hybridization, and sigma and pi bonds. We learned some this stuff last week too but this week we put it all together with our VSEPR WebMO lab. WebMO is a program created by Hope college which allows us to model molecules. It is very helpful as it provides a good visual to molecules and provides many important details about the molecule. Using WebMO, we modeled 13 molecules and found the electron domain geometries, molecular domain geometries, dihedral angles, dipole moments, and many other things You can see my full report on this lab here:
     We came to understand all of these ideas this week through our POGIL with balloons and gum drops and the lab we did using WebMO. The lab report was kind of the icing on the cake which tied the two together. I feel like I understood everything which went into the lab report pretty well but I still have some questions regarding ionic and covalent bonds and how they tie into what we've learned. I think  participted very well in this past weeks assignments, I did all of my WebMO molecules without any issues and also was able to do my lab report and study for the upcoming test. I think I still need to work on getting lewis structures down faster because I feel like at times it takes me too long to draw them out. One thing that  really gets me thinking is the molecule BrF5 (Bromide pentafluoride). I found this molecule interesting because its unpaired electron cloud does not effect the original angles that would be made in an octahedral model made with all paired electron clouds.

Blog Post #5

     This past week has been very busy as we've learned about several new topics. Some of the main ideas we've learned about are the shapes that molecules make and polarity. The shapes made by molecules are dictated by bonded and unpaired electron clouds. This is known as the VSEPR theory. We also learned about how molecules have poles and some, based on their shape, have polarity. These ideas are connected because often polarity is dictated by shape. If a molecule's shape is symmetrical, the individual poles of electrons can cancel out meaning that the molecule as a whole has no polarity. Some important details about the VSEPR theory are that electron domain geometry shapes are often much different than molecular domain geometry shapes. This is because electron domain shapes include unpaired electrons while molecular domains do not. A important detail about polarity is that based on the molecular domain shape, polarity can cancel itself out if they're pulling in opposite directions. We did multiple POGIL's this week regarding  the VSEPR theory. The most interesting was our POGIL were we made electron domain shapes with balloons and molecular domain shapes with gumdrops and toothpicks. We also practice more Lewis structures with POGIL 14 and  POGIL 15. Through these POGIL's we learned about charges and resonance structures. We also learned about polarity through a lecture and a lecture quiz.
     We learned a lot this week and I'm definitely still a little cloudy on some subjects. Most of the questions I have are just some clarification questions regarding polarity and molecular domain shapes. I think my participation was good this week as I did all of the work and pitched in to help my group on the POGIL's. My understanding of this week's material was not as good as I'd like. I will try to fix this by reviewing the lectures again or trying to go after school some more. I still need to work on understanding polarity better and recognizing electron domain shape. Some new things I have to think about are electron clouds. I find it interesting how they can be different sizes and how they all affect each other.

Blog Post #4

     In this past week we mostly focused on our lab (That's rather brass of you, Cu) and we also began learning about Lewis diagrams. In the lab, we looked to find the mass percent of copper in a brass screw after dissolving it in nitric acid. We also learned about Lewis diagrams which are a simple way to show valence electrons and bonds in molecules. These two ideas tie well with each other because brass is actually a molecule made up of copper and zinc. In the lab, the nitric acid actually breaks down the bonds between the copper and zinc. This connects to Lewis diagrams because they represent the valence electrons and bonds in molecules. Lewis diagrams can help detail many things in a very simple way. Some details that Lewis diagrams can show are, charge, bond length, and bond order. All of these things are very helpful in identifying a molecule. We learned about the Lewis Diagrams this past week through various POGIL's and lectures. We also began to look at how bonded electron clouds look in terms of shape. We did this in a POGIL that involved tying balloons together. (See picture). The balloons are actually a fairly accurate way to portray electron clouds and really helped me visualize the shapes. The method that really allowed me to best understand the material we covered this week were the lectures. The lectures really helped me because you can watch concepts you don't understand over and over and then test your knowledge on the lecture quiz.
     A question I still have about this material is, how are triple bonds actually possible? I understand how quadruple bonds aren't possible but it doesn't really make sense to me how triple bonds actually work. I think my participation in this weeks material was good. I did all the homework and all the POGIL's so I feel like my participation was good. I'd say my one slip up however, was when our group forgot to add water to the copper solution before measuring its absorbance. I'd rate my understanding of this weeks material at about a 6 or 7. I feel like I understand what's going on but I definitely need to practice complex Lewis diagrams more and go over the electron cloud shapes. One new thing I have to think about after what we learned this week is, what happened to the zinc when we dissolved the brass screw with nitric acid and does it affect copper's absorbancy?

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.