Density of Solids and Liquids
Honors Chemistry Lab
Objectives
The objectives of this laboratory are:
a) To determine the density of Aluminum (applying the technique of water
displacement) and to use it to determine the thickness of a piece of aluminum foil.
b) To determine the volume of a regularly shaped solid via its measured dimensions.
c) To determine the density of pure liquid water and pure liquid ethanol.
Background
Volume is the amount of space occupied by matter. Volume is an extensive property. An
extensive property is one that is dependent on the amount of matter present. In other
words, the greater the quantity of a substance, the larger the volume of that substance.
The volume of a liquid can be directly measured with specialized glassware, typically in
units of milliliters (mL) or liters (L). Note that when measuring liquid volumes, it is
important to read the graduated scale from the lowest point of the curved surface of the
liquid, known as the liquid meniscus.
Measuring the Volume of Liquid
Here, the graduated cylinder markings are every 1-milliliter.
When read from the lowest point of the meniscus, the correct
volume reading is 30.0 mL. The first 2 digits 30.0 are known
exactly. The last digit 30.0 is uncertain. Even though it is
a zero, it is significant and must be recorded.
The volume of an irregular solid must be measured indirectly based on its shape. For
regularly shaped solids, such as a cube, sphere, cylinder, or cone, the volume can be
calculated from its measured dimensions (length, width, height, diameter) by using an
appropriate equation.
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Formulas for Calculating Volumes of Regularly Shaped Solids
Volume of a cube = l x w x h
Volume of a sphere = 4/3 πr3 where r = ½ the diameter)
Volume of a cylinder = πr2h
Volume of a cone = 1/3 πr2h
For irregularly shaped solids, the volume can be indirectly determined via the volume of
water (or any other liquid) that the solid displaces when it is immersed in the water
(Archimedes Principle). The units for solid volumes are typically cubic centimeters (cm3)
or cubic meters (m3). Note that 1 mL = 1 cm3.
Measuring the Volume of an Irregularly Shaped Solid
Volume water displaced = Final volume – Initial volume
Volume water displaced = Volume of solid
Density is defined as the mass per unit volume of a substance. Density is a physical
property of matter. Physical properties can be measured without changing the chemical
identity of the substance. Since pure substances have unique density values, measuring
the density of a substance can help identify that substance. Density is also an intensive
property. An intensive property is one that is independent of the amount of matter
present. For example, the density of a gold coin and a gold statue are the same, even
though the gold statue consists of the greater quantity of gold. Density is determined by
dividing the mass of a substance by its volume:
Density 
Mass
Volume
Density is commonly expressed in units of g/cm3 for solids, g/mL for liquids, and g/L for
gases.
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In Part A of this lab, the mass and volume of a sample of aluminum will be measured in
order to determine its density.
In part B the experimental density will then be used in an applied problem to determine
the thickness of a piece of aluminum foil.
In Part C the density of water and ethanol will be determined
Procedure
Safety
Be especially careful when adding the aluminum to your graduated cylinder, as the glass
could be broken. Also, ethanol is flammable, so avoid using it near an open flame.
Although pure ethanol is in alcoholic beverages, the ethanol you are using has been
denatured. This means it is unsafe to drink. Don’t even think about it.
Materials and Equipment
10-mL graduated cylinder, 50 mL beaker, metric ruler, aluminum pellets, aluminum foil,
electronic balance, ethanol, pipets
Part A: The Density of Aluminum
1) Obtain a sample of aluminum pellets from your instructor. The pellets will be
labeled 1-5.
2) Using the electronic balance, determine the mass of each pellet. Record this in
your data table.
3) Pour about 5 mL of water into your 10-mL graduated cylinder. Precisely note this
volume. Record it in your data table. (It should be to 2 decimal places)
4) Carefully add one aluminum pellet at a time to the water, making sure not to lose
any water to splashing. Also make sure that the pellets are all completely
immersed in the water. Measure the new volume after each pellet has been added.
Record this in your data table.
5) When finished, retrieve and dry the aluminum pellets and return them to their bag.
Part B: The Thickness of Aluminum Foil
1) Obtain a rectangular piece of aluminum foil.
2) Use the ruler to measure the length and width of the piece of foil in cm.
3) Fold the foil up into a small square and measure its mass using the electronic
balance. Record this in your data section.
4) When finished, throw away the foil, and return the meterstick.
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Part C: The Density of the Liquid Water and Ethanol
Ethanol
1) Using the electronic balance, obtain the mass of your clean, dry 10-mL graduated
cylinder. Record this in your data section.
2) Add approximately 5 mL of pure liquid ethanol to the 10-mL graduated cylinder.
Use the pipet attached to the bottle of ethanol. Record the volume of ethanol used
in your data section.
3) Now obtain the mass of the cylinder and ethanol. Record this in your data section.
4) Pour your ethanol into the waste ethanol beaker.
5) Rinse your graduated cylinder out with water. Be sure to dry the entire outside.
6) Add approximately 5 mL of tap water to the 10 mL graduated cylinder, using
your dropper pipet. Record the volume of water used in your data section.
7) Now obtain the mass of the cylinder and water. Record this in your data section.
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Name ________________________________________
Block __________
Data
Part A
Volume of Water in 10.00 mL graduated cylinder
Pellet #
Mass (grams)
1
2
3
4
5
Volume
Pellet #1 Added
Pellet #2 Added
Pellet #3Added
Pellet #4 Added
Pellet #5 Added
Part B
Length of Aluminum Foil
Width of Aluminum Foil
Mass of Aluminum Foil
Part C
Mass of clean dry 10 mL graduated cylinder
Volume of Ethanol Added
Mass of Ethanol and cylinder
Volume of Water Added
Mass of Water and cylinder
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Calculations
Part A
1) Calculate the volume of each aluminum pellet in cm3.
2) Determine your experimental density of aluminum based on the total volume of
aluminum and total mass of aluminum.
3) Look up the actual value for the density of aluminum and calculate your percent
error.
( Actual  Experimental )
PercentError 
x100
Actual
Part B
1) Use your calculated (experimental) density of aluminum to determine the
thickness of aluminum foil. (In millimeters)
Part C
1) Determine the mass of ethanol used.
2) Calculate the density of ethanol.
3) Look up the actual value for the density of ethanol and calculate a percent error.
4) Determine the mass of water used.
5) Calculate the density of water.
6) Look up the actual value for the density of water and calculate a percent error.
Questions
Part A
1) Explain why the density of aluminum is considered a physical property?
2) Is aluminum a mixture or pure substance? Explain your reasoning.
Part B
No questions
Part C
1) Propose reasons why the density of ethanol is different than the density of water.
Discussion of Theory -- What scientific principles allow this lab to be performed.
Discussion of Error -- Not human error. What can cause your results to be off. P.S.
This lab does not have any experimental error.
Conclusion – Summarize your findings. What did you learn?
Reference
Adapted from:
Chemistry 10 Lab Manual. Santa Monica College. 12 Jan. 2005
<http://homepage.smc.edu/chem10/Experiments.html>.
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