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Lab Report Example
Introduction:
Density is a measurement of the amount of mass that fits within a specific volume
(Nagel). Substances with different densities interact in varying ways with their own individual
densities. The standard against which the density of different liquids is compared is to that of
water. Water has a density of 1.0 g/mL. Any substance with a density greater than this will sink
in water, while any substance with a density lesser than this will float on water (Lower). This
phenomenon is called buoyancy and this lab will show the relative buoyancies of five different
liquids by determining and comparing their densities.
Materials & Methods:
In this lab, the density of several liquids and their relative buoyancies were explored. In
order to determine density, the volume and mass of each liquid was measured. Volume was
found by placing a sample of a liquid in a clean graduated cylinder, making sure to note the mass
of the cylinder beforehand, and the volume recorded. The mass of each liquid was determined
by using a balance to take the mass of each liquid in the graduated cylinder, subtracting the mass
of the cylinder to obtain the mass of the liquid, which was then recorded. These steps were
repeated for all liquids, making sure to clean out the graduated cylinder in between.
Results:
Liquid
Water
Alcohol
Dish soap
Corn syrup
Baby oil
Mass
(g)
48.4
44.6
52.6
70.4
40.6
Volume
(mL)
50
Density
(g/mL)
0.968
0.892
1.052
1.408
0.812
Order of
Relative
Density
Math
3
2
4
5
1
48.4 g ÷ 50 mL = 0.968 g/mL
44.6 g ÷ 50 mL = 0.892 g/mL
52.6 g ÷ 50 mL = 1.052 g/mL
70.4 g ÷ 50 mL = 1.408 g/mL
40.6 g ÷ 50 mL = 0.812 g/mL
Discussion:
The information gathered from this procedure shows the relative densities of five
different liquids. As the volume remained the same throughout, it was also possible to relate the
relative mass to a substance’s buoyancy. With identical volumes of 50 milliliters, it was found
that the least dense liquid is baby oil, while the most dense liquid is corn syrup. These
differences in density became apparent when all liquids were placed into the same container.
The densest liquid, corn syrup, sunk to the bottom of the container, while the least dense liquid,
baby oil, floated on the top of all other liquids. This occurs because the volume of liquid that
would displace the same volume of water has a lesser weight than the water so it floats, whereas,
when the reverse is true, it sinks (Buoyancy).
Accurate measurements are very important in this experiment. Should a mass or its
constituent volume be misread, this affects the density calculation. As can be seen in this lab
with water, whose accepted value for density is 1.0 g/mL, the calculations show water to have a
density of 0.968 g/mL, which is off by 3.2%. Other errors are possible in the massing of
substances within the same graduated cylinder. It is also possible to have inaccurate
measurements if any previous liquids are left in the graduated cylinder. Aside from human error,
the balance was not calibrated before measurements were made, so accuracy cannot be
determinedly assumed (American Weigh Scales).
Lab Report Example
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Works Cited:
American Weigh Scales. Scale Terminology Database. Online. AWS: 2009. 08 November
2009. < http://www.awscales.com/support/terminology>
"Buoyancy." Science of Everyday Things. Online. Detroit: Gale, 2009. Science Resource Center.
Gale. 08 November 2009.
<http://galenet.galegroup.com/servlet/SciRC?ste=1&docNum=CV2643602008>
Horn, Molly. Laboratory Manual: Honors Chemistry. Franklin, NH: Franklin High School.
2009.
Lower, Stephen. “Understanding Density and Buoyancy.” Chem1 General Chemistry Virtual
Textbook. Simon Fraser University. 08 November 2009.
<http://www.chem1.com/acad/webtext/pre/density.html>.
Nagel, Robert (Ed.). "Density." U*X*L Encyclopedia of Science. 2nd ed. Online. Detroit:
U*X*L. 2007.