Sugar Cubes: Sweet and Scientific!

        This past week in science class, we did an interesting lab with sugar cubes.  There were two different parts of our experiment.  In Part A, we had to perform and observe physical changes while in Part B, we had to do the same with chemical changes.  

PART A:

        First, we had to just take two sugar cubes and observe them.  They were cubed, white, and kind of looked like Styrofoam.  Next, we used a mortar and pestle to crush them into a powder.  It had no shape and felt much lighter and softer than the untouched sugar cubes had.  After this, we took the crushed sugar and poured it into a glass of water.  We found that we could see minuscule pieces of the sugar floating about in the water even though most of the sugar had settled down at the bottom of the glass.  Soon, the sugar started to dissolve.  If we weren't allowed to taste the water to see if the sugar was still there, we could look in a microscope or perform an experiment (leave the glass of water to evaporate so that we could see if the sugar was at the bottom).  

PART B:

        In this part, we received two new sugar cubes and placed them in a test tube.  As the test tube heats up, a yellowish substance starts to form.  I was surprised since the yellow was a mushy kind of color that I didn't think would come from pure white sugar.  Soon enough, the substance bubbles until it changes to a mostly black color (there is some brown and yellow, though they are sparse).  It smells like marshmallows at first, but then a burnt aroma is in the air.  We take the test tube of the Bunsen burner, break it, and observe the new substance.  It had no definite size anymore and the hardened liquid was mostly flat against the glass.  However, I can still see some of the sugar cubes (at least one of them).  I can tell because it is pretty much the only part that juts out, has a significant corner (like an untouched sugar cube), and is a light brown color. 


My Thoughts and More:

          I thought that this experiment was a good way to reinforce what we learned about physical changes, chemical changes, and chemical reactions.  This is because we were told to determine what the difference between Part A and Part B was and we had to describe what made them different.  We discovered that Part A was a physical change because we changed the sugar cubes in only a physical way by crushing them.  On the other hand, Part B was a chemical change because we were burning the sugar and burning a substance is a chemical change (found in our T-chart in our notebook).  The process of actually doing the experiment hands on and using what we already learned to identify scientific concepts by ourselves has definitely helped and built on the way we do experiments and take notes on them.  
         In our textbook, it describe chemical changes, chemical properties, and physical properties.  A physical property can be things like mass, weight, volume, density, texture, and many other things that describe what a substance is like.  A chemical property is the property that describes how a substance changes into one or more other properties.  A chemical change is process or changes that a substance undergoes to turn into other substances. These three are closely related, however, they are different in their own ways.  
          Now, to be more general, I'm going back to the original substance: sugar.  Sugar can be used in many ways.  As we already learned, it can be burned and crushed.  Sugar is mostly used to sweeten foods (or products). Also, I learned that sugar, when dissolved in water, can be made into a syrup. Even though we did exactly this in Part A, I hadn't realized that it had turned into a kind of syrup until now.  In addition, today, I learned that any food related word that ends in "-ose" is likely to include sugar in it. Though I partly knew the previous fact, I found these two facts to be very interesting for the reason that I didn't really know them before and they seemed to be extremely simple - which is why I was surprised that I hadn't realized them.
        After participating in this lab, I'm sure that I'm speaking for everyone when I say that it was enlightening and fun to take part in.  I think that this experiment helped reinforce what we learned a few weeks ago.  Hopefully, we will do a lab just as fun or even more than this one was soon!


Two Sources:
Matter: Building Block of the Universe  (textbook)
http://en.wikipedia.org/wiki/Sugar


This is the link to the picture I used:
click here


~Starflower794