Week 4 Reflective Post

Probably the biggest point of this unit is the mole.  The mole is what we've been focusing on for the past week.  We've done sample problems involving this concept and we also did a lab to further educate ourselves.  To quickly review the stuff we covered the week before, we did another worksheet with relative mass, but this time, we also introduced the mole a bit more.  As we got through the worksheet, we continued to do relative mass problems and by the end, we had related those to the mole, and had learned that there are 6.02x10^23 atoms in one mole.  This one concept is very important as it's what we focused on throughout the whole week.

To further our education on the mole, we did a worksheet that just had number problems involving the mole.  We were given a number of scenarios and from there we had to calculate relative mass using our knowledge of the mole and how it relates.  I really liked this worksheet because it helped me solidify my understanding of the mole and how it relates to relative mass.  We continued practicing our knowledge of the mole in the first couple days of the week, but during the middle of the week we started a lab.
This lab was called the Empirical Formula lab, and it mainly focused on the mole.  To start off the lab, we had to measure the mass of a beaker, and then the mass of that same beaker with a couple grams of zinc in it.  Once we had measured these out, we poured 50 mL of HCl into the beakers, and then we put them in the fume hood for the rest of the day.  The next morning we got to class and we had discovered that the reaction between the Zinc and HCl had formed a crusty like substance.  After this discovery, we heated up the substance to get rid of any excess water so we could take the final mass of the compound formed.  From this point, we calculated the masses of the two elements reacted and also how many moles were in each element.  Our final task was to find the likely whole number ratio between the two elements reacted and also to write out what we thought the chemical formula would be.  Finally, after we had done all the busy work, we wrote our data up on the white board and compared it with other groups data.  For the most part, we had gotten around the same values, but for some reason our ratio we discovered was almost 3:1, not 2:1.  Seeing this, we realized that we had made a mistake in our calculations, because every other groups ratio was 2:1.  We couldn't pinpoint the exact area of scientific error, as there were many contending spots.  Overall though, this lab taught us (in a fun way) how to discover the masses and moles of elements an compounds with just a simple amount of information.

To finish off the week, we we're given a worksheet that we were to do over the weekend.  It was another worksheet that covered moles and how to calculate them with just the given mass and formula of an object.  It was actually a very helpful worksheet as it gave us more practice and helped us solidify the concepts we learned this week.  I'm excited to keep learning and doing fun labs such as the one we did this past week.  Who doesn't like using fire in class?