Chemistry Reflection One

With two weeks of school completed, I have started to have a feel for all of my classes.  I have been very nervous about this year because I have quite a lot on my plate, but so far, while I know that the first two weeks are slightly different from the rest of the year, it looks like things will be working out fine.

These past two weeks, we have focused on the ideas of the mass of an object, physical and chemical changes, and on volume.  The mass of an object is the amount of matter in an object and volume is how much space that an object takes up.  These measurements can be altered when an object undergoes a change.

          To learn about mass, we did a lab that consisted of eight experiments.  In each lab, we weighed the object before and after to demonstrate how the object’s mass changed, if at all.  The experiment that I found most interesting in this lab was when we put Alka-Seltzer into a bottle of water.  Below are the details for this experiment. 

When our group performed this experiment, we found that the mass decreased by .07mg because gas was released from the top of the bottle.  Another experiment that we did was to take a piece of steel wool and hold it over a Bunsen burner.  The mass of the steel wool increased by .18mg because it took in oxygen.

          We also did a lab to demonstrate whether or not a change was a physical or chemical change.  In one experiment, we combined iron chloride and thiocyanate.  The iron chloride was a yellow color, and the thiocyanate was clear.  When we combined them in a beaker, the result looked like this:

The new substance was thick and a dark red, resembling blood.  This was an example of a chemical change.  We knew this because the color change was unexpected.  In another experiment, we dropped a piece of Zinc into a beaker of dilute sulfuric acid and the Zinc began to bubble and fizz.  The Zinc was reacting with the dilute sulfuric acid.

          Finally, we began to learn about volume and how to measure volume.  We practiced this by measuring volume in both milliliters and centimeters³.  Each group was given a container.  It was either a box or a cylindrical bottle.  My group got the bottle.  We then marked the bottle at different heights and found the volume at those different heights in cm³.  Then, we filled the bottle with water up to the lines that we had marked, and poured all of that water into a graduated cylinder to measure it in mL.  Lastly, we put our data into Microsoft Excel and made a graph, which we copied on to a whiteboard to share with the class.  When we discussed our answers as a class, we decided that measurements in cm³ are far more precise than measurements in mL.  Here are some pictures from this lab:

It’s pretty clear that we covered a fair amount of information.  Along with that, we have been able to get to know each other as a class, which is a good thing since we will have to work together in the months ahead.  I feel that I have been a team player and have worked with my lab partners well and that I accomplished a lot.  I may have been afraid to be in Accelerated Chemistry at the beginning of the year, but I know now that this will be a very fun, very engaging class and I look forward to the rest of the year.