Accel Chem Blog #4

        This week we learned about 3 main topics: Balancing equations, different types of chemical reactions, and we did an activity series in which we had different examples of the types of chemical reactions.
        The first topic we learned about was balancing equations and the different steps. First you have to write the correct formula for all reactants and products. Then, you have to adjust the coefficients so that the total number of reactant atoms equal the number of product atoms. We learned something during class about how you could use 1/2 s just to help balance but I have had enough practice balancing equations that I can do with out it. We have to balance equations to know the exact amounts in which they react.
          The second topic we worked with is types of chemical reactions. There are 5 different types of reactions. The first is a Synthesis or Combustion reaction. This is when you have two reactants become one product. For example Na + S --> Na2S. The second is a Decomposition which has one reactant which breaks into two through being heated. For example, 2Ag2O --> 2Ag + O2. The third type of reaction is Single Replacement. This is when you have one element and a compound. If the element you have is a metal, then the metal in the compound swaps out with that element. For example, A + Bx --> Ax + B. This can sometimes happen where the element is a non-metal and the non-metals switch but that is rare. That's the best way I can explain it. The next example is a double replacement. This is when you have two compounds and the metals switch places. For example, Ax + By--> Ay + Bx. The last type of chemical reaction is called a Combustion reaction. This is when you have a Hydro Carbon and Oxygen is present for the reactants, producing Carbon Dioxide and Water in the products. You need oxygen present because you have something being lit in all of these situations and oxygen must be present. We learned about all of these by doing the activity series where we did experiments. In the experiment we used litmus paper and splint tests to determine what was produced. Here is a picture example of a combustion reaction.


       The purpose of this week was to be able to balance chemical equations and tell what type of reaction occurred. When I reflect on the week it was more of a re-emphasis of what I already knew with some added. I already knew how to balance equations and knew some of the chemical reactions, but I did not know the names of the reactions or about the combustion reaction before this week. Doing all the experiments over the week made it fun though compared to just learning it in our desks.

Accelerated Chemistry Periold 1 Blog 3

To start the week we were put into groups of 3 where we worked on worksheet one. Here we learned about Daltons Assumption and Avagadro's number. Dalton assumed that the lowest ratio for compounds was 1:1. We found that this worked, but was not quite accurate every time. We learned that each mass listed on the periodic table is compared back to Carbon-12 because it is the most abundant, instead of comparing it to Hydrogen, which isn't as abundant. Avogadro's Number is the number of atoms in 12 groups of C-12 which is 6.02*10^23. The next day we learned that this number is called a MOLE!



 

We learned that it is spelt the same as the animal mole, but is actually a number! We then got a worksheet that showed us how big the number mole actually was. When you here the number you think it is big, but this worksheet showed how humongous the number is. This day we also got our colored periodic table of elements which shows us the element and its molar mass. We learned that the Molar Mass of every element is on the periodic table. The last thing we did was do a lab on molecules of water in your mouth, and how many Pepsi cans are needed to contain 8.45*10^23 atoms of aluminum. I won't write to much in this about the experiment because I already did that in my conclusion, but the real purpose of this was to get us used to converting between moles and molecules. Throughout the week we did plenty of this. I did not really like having to write the For Every Statements for each one because often times this made me over think every question. Otherwise, I think the practice was useful because it got us used to doing the calculations. The last thing that we learned was percentage composition. This is a very easy topic to understand. All you do is take the compound you are using and take the one you want and divide it by the total. This is hard to understand so I will give an example. If you have water, so H(2)O and you want to find the percentage composition that Hydrogen is of water, you take 2, which is the atomic mass of 2 hydrogen's, and divide it by 18, which is the total atomic mass of water. So you take what you want to find, divided by the total.
 

If I was to look back on the week I would say I learned and understand everything about moles. Like I said earlier I didn't really like having to write the For Every statement every time at the beginning of the unit. I also thought we did to many examples, but I can say I understand Moles well.