Discovering which Substance is which

          During this lab, my group was given three cubes (all different elements/compounds), and we had to discover what they were made of using the mass, length, width, and height of the cubes.  To figure out what kinds of materials we had, we needed to figure out the density of each cube.  The density of something is the mass of the object divided by its volume (D = m/V).  That meant that we had to work out the volume of each cube.  Luckily each cube was exactly the same size, and since volume is length times width times height (L*W*H), all we had to do was measure one side of each cube and cube it.  All the sides of each cube were 2.5 cm long, so we cubed 2.5 cm and got a volume for each as 15.625 cm cubed.  We then measured the mass of each cube and divided them by 15.625 to get their densities.  Here are our results:

• Cube I:   0.6976 g/cm cubed
• Cube II: 0.9664 g/cm cubed
• Cube III: 1.504 g/cm cubed

Then, we looked at our charts and, according to density, Cube I was made of oak; Cube II was Polypropylene; Cube III was PVC.  

PVC

Oak

Polypropylene

          Of course, there were many places where we could have made mistakes.  There could have been flaws in the cubes themselves.  There might have been mistakes in the Balance we used to measure the mass of the cubes.  The rulers we needed to measure the sides of the cubes could have been incorrect.  We could have done something wrong.  This means that the results above are not completely accurate.  There are probably errors that have altered the numbers above.  In order to fix this, we could make sure the Balance and rulers are as accurate as possible.  We still would not be able to get everything completely right, but we could get pretty close.