CHEM 111
Chris Brendel
Partners: Meghan Hudson, Rachel Collister
1/1
Density
5/16/11
The aim of the experiment was to calculate the density of water (de-ionized and tap), to
calculate the density of a rubber stopper, and to acclimate the student to basic laboratory equipment. In
order to determine the density of the water samples, we used a buret to measure out amounts of both
de-ionized and tap water, used a balance to determine the mass and noted the volume of each sample.
We measured the mass of the rubber stopper and then calculated its volume through two separate
methods: dimensional analysis (using a ruler) and water displacement (in a graduated cylinder). Using
the mass and volume figures, we determined the DI water sample to have a density of .9949 g/mL and
the tap water sample to have a density of .9947 g/mL—these results could be attributed to
experimental error, as properly de-ionized water should be less contaminated than tap water and
therefore less dense. Using the equation V = ((π*h)/3)(R^2+Rr+r^2) and the previously measured mass,
we determined the rubber stopper’s density to be 1.6 g/mL, which agrees with the density 1.6 g/mL
calculated by the more-accurate water displacement method.