Blog Reflection; Week of 9/8/13

Blog Reflection by Raymond Zhao hour 1
     In the past week, we did and learned many things. Some significant ideas we learned were about Molarity, Stoichiometry, Absorbance, Transmittance, Concentration, Spectrophotometry, and the calculations involved with all the ideas.  I learned that:
-Molarity means moles/1 liter and it is unit for Concentration. Molarity was used in the lab we did about Concentration and transmitted light
-Stoiciometry is a branch in chemistry that involves balancing the chemical equation by alerting the coefficients of the reactants and products
-Absorbance is the amount of a certain wavelength of light absorbed by a solution. Is is related to transmittance by the beer's law; Absorbance = -log (percent transmittance/100)
-Transmittance is the amount of light transmitted through a solution it is related to absorbance by the beer's law; Absorbance = -log (percent transmittance/100)
-Concentration is the amount of something is in something and it is measured by the unit of Molarity (moles/1 liter)
-Spectrophotometry is the science of measuring the absorbance or transmittance and calculating the concentration from it\
-M1V1=M2V2
-Beer's law: absorbance=-log(%transmittance/100)

     These ideas all are very important to chemistry. After doing the concentration and transmitted light lab, I have learned that Absorbance, Concentration, Transmittance, Spectrophotometry and Molarity are all connected. Absorbance and Concentration has a direct relationship with each other because as concentration increases, absorbance increases and vice versa. Absorbance and Concentration has a negative correlation with  transittance. Also, Molarity is used to measure Concentration, like how the concentration of the blue dye was measured in micromoles per liter. All of these ideas are all used in Spectrophotometry to find the concentration.
     Learning these ideas was so-so regarding difficulty. I felt that learning them was challenging, but not so hard that I don't get it. The lectures, lecture quizes, class disscussions, and the lab all greatly helped my understanding of these key ideas. The most challenging part was finding the mass of the blue dye in the sports drink like G2 and power aid. However, working in groups allowed me to learn how to find the mass. Now, I almost fully understand the material taught for the past week; I would rate it about a 9.5/10. The thing I have a question about from last week is about Stoichiometry and how to do it correctly because Dr. Finnan does it a special way that results in less mistakes. My participation in the past week also greatly helped my understanding because I learned many new things by participating and asking questions. I would rate my participation a 9.5/10 too. My only question is what is the actual (accurate) relationship between the concentration and absorbance in the lab? I know different classes got different results. In addition, I still need some more practice with using M1V1=M2V2 because I get confused sometimes.
     After this week, my thoughts on the characteristics of solutions and light changed. In the past, I would never think about the transmittance or absorbance of a solution, but now i do. This is because I learned new ideas through the lectures, lecture quizzes, class discussions that we did. Each of the activities added to my knowledge and the result was me understanding about all of the required material.

This is the chart of concentrations and absorbances from the lab

 

This is a link to the lab introduction and procedure

This is a link to beer's law