UNIT 5
For this unit, Unit 5, as well as the whole first half of the year in this Accelerated Chemistry Class, I have learned an incredible amount. In this short period of time, we traveled all across the globe of chemistry too subjects such as relative mass, Avogadro's number, Avogadro's formula, and even as far as moles? Eventually we got to subjects like Molar mass and calculations using the magical number 6.02x10^23 and empirical formulas.Relative Mass
In this sectioned, I learned the ratio of masses when comparing different substances to another. For example, we measured one dozen popcorn kernels, one dozen grains of rice, and one dozen beans. What was then completed is stated as follows: In any sort of large mass measurement, we are now able to figure out how many pieces of the one substance is inside a large container- this applies to atoms too, where the amounts of invisible atoms can be counted to precise accuracy. For example, if I had a glass beaker with Helium inside, I would be able to tell how many atoms of helium are inside that beaker.
Moles
No, these aren't the standard everyday hole-digging, lawn raising pests, this is actually a very important number to all of chemistry. 1 Mole is equal to 6.02x10^23 molecules of any substance. For example, 1 mole of moles would weigh about equal to our moon. One mole of grains of rice is larger than all of the world's crop at any given time. Yeah, it's a big number. The reason that it is so important is the fact where it can be used to figure out how many atoms or molecules are located in a certain substance.
In one very important lab, we determined how many pieces of chalk would be needed to contain 1.25x10^24 molecules. To do this, my lab group and I weighed out I piece of CaCO3 (shown below) to figure out the mass in grams. Then we determined the Molar Mass of chalk by adding up the appropriate element masses on the periodic table and equated them into a series of proportions. (molar mass (g)/6.02x10^23 molecules=X(g)/1.25x10^24 molecules) We determined that around 7.67 pieces of chalk were needed for that said amount.
We also completed a similar lab in this unit that allowed us to find the number of water molecules in an average's person's mouthful of water. (In this case, it was Pat's.) To find this out, we filled up a cup with a good amount of water, weighed it (minus the beaker of course) and had Pat fill his mouth to the brim (which kinda got messy, but oh well...). We then weighed the water after and subtracted the final amount from the initial to get the amount in grams, and then we set up a formula to figure the amount of molecules in his mouthful. All in all, they were successful labs to drive home the subject of Avogadro's Number...
Lastly, we Worked on Empirical and Molecular Formulas. The empirical formula allows for the finding of the parts of a compound to be discovered, for example, when we dissolved Zn in HCl overnight, evaporated the water, and found out how much Zn Chloride was produced.
I feel very strong in my ability to calculate and figure out chemical formula and empirical equations, and there is a possibility I have a little more understanding in this topic than some of my classmates. I was not very talkative this unit, and could stand to be, but I will definitely try to strengthen my confidence in answering questions and raising my hand. Overall, I completed everything on time, and soaked it all up consistently, so I can only resort to one thing right now. You get another A for teaching this unit, Mr. G....
