Last updated Dec. 2013
Chemistry 151
Lab 3: Density of Solids and Liquids
Introduction
In this lab we will explore common methods for measuring density. With liquids, one can simply measure
the mass with a balance, the volume with a graduated cylinder, and then take the ratio of the two. For
solids objects, if it’s a simple shape, you might be able to determine its volume by measuring its size and
find it’s volume mathematically. However, an alternate method for measuring volume, which is especially
useful when the shape is irregular, is an indirect method known as water displacement. If you place the
object in a known volume of water, the water level will increase by a volume equal to that of the object.
Procedure
PART I: Determining the density of a liquid.
1. Measure the mass of a 10 mL graduated cylinder.
2. Measure approximately 5 mL of rubbing alcohol using the graduated cylinder from step 1.
3. Measure the mass of the graduated cylinder with the liquid, and then determine the mass of your liquid.
4. Using the mass and volume the liquid, determine its density.
5. Repeat steps 1-4 using ~7 mL of alcohol.
6. Repeat steps 1-4 using ~10 mL of alcohol.
PART II: Determining the density of a solid using water displacement
1. Find the mass of a rubber stopper.
2. Using a graduated cylinder, measure 25-50 mL of water.
3. Slightly tilt the graduated cylinder and carefully slide the rubber stopper into the water. Measure the
new volume of water.
4. Use the mass and volume of the rubber stopper to determine its density.
5. Repeat steps 1-4 twice more, each time using a different sized rubber stopper.
PART III: Direct Measurement vs. Water Displacement
1. Measure the mass of a glass tile.
2. Measure the dimensions of the tile and use this to determine its volume.
3. Determine the density of the tile using its mass and volume.
4. Determine its density a second time using water displacement to measure its volume. For smaller tiles, it
may be necessary to use more than one tile to displace the water by a measurable amount.
5. Repeat steps 1-4 using a different sized tile.
PART IV: Determining the density of an unknown metal
1. Your instructor will give you a metal. Use the water displacement technique to determine its density.
2. Identify the metal from the following list:
Metal
Aluminum
Bismuth
Magnesium
Nickel
Zinc
Titanium
Density (g/mL)
2.7
9.8
1.7
8.9
7.1
4.5
Waste Disposal
The alcohol can be returned to the bottle to be reused by future sections (note: this is the only time you’ll
ever do this during a lab). Water can be poured down the drain.
Name: _____________________________
Section: ________
Data
Note: for this and future lab reports, all measurements and calculations should be recorded using the correct
number of significant figures.
PART I: Determining the density of a liquid.
Trial 1
Trial 2
Trial 3
1) Mass of graduate cylinder (g)
__________
__________
__________
2) Mass of graduated cylinder and liquid (g)
__________
__________
__________
3) Mass of liquid (g)
__________
__________
__________
4) Volume of liquid (mL)
__________
__________
__________
5) Density of liquid (g/mL)
__________
__________
__________
6) Average density (g/mL)
__________
Show your work for determining the density of Trial #1
PART II: Determining the density of a solid using water displacement
Trial 1
Trial 2
Trial 3
1) Size of rubber stopper
(number code on top)
__________
__________
__________
2) Mass of stopper (g)
__________
__________
__________
3) Initial volume of water (mL)
__________
__________
__________
4) Water volume after addition of stopper (mL)
__________
__________
__________
5) Volume of stopper (mL)
__________
__________
__________
6) Density of stopper (g/mL)
__________
__________
__________
7) Average density (g/mL)
Show your work for determining the density of Trial #1
__________
PART III: Direct measurement vs. water displacement
Direct Measurement:
Trial 1
Trial 2
1) Mass of tile (g)
__________
__________
2) Length (cm)
__________
__________
3) Width (cm)
__________
__________
4) Height (cm)
__________
__________
5) Volume (cm3)
__________
__________
6) Density (g/mL)
Note: 1 cm3 = 1 mL
__________
__________
7) Average density (g/mL)
__________
Show your work for determining the density of Trial 1.
Water displacement:
1) Mass of tile (g)
__________
__________
2) Initial volume of water (mL)
__________
__________
3) Water volume after addition of tile (mL) __________
__________
4) Volume of tile (mL)
__________
__________
5) Density of tile (g/mL)
__________
__________
6) Average density (g/mL)
__________
Show your work for determining the density of Trial 1.
PART IV: Determining the density of an unknown metal
Unknown #: __________
Trial 1
Trial 2
Trial 3
1) Mass of metal (g)
__________
__________
__________
2) Initial volume of water (mL)
__________
__________
__________
3) Water volume after addition of metal (mL)
__________
__________
__________
4) Volume of metal (mL)
__________
__________
__________
5) Density of metal (g/mL)
__________
__________
__________
6) Average density (g/mL)
Show your work for determining the density of Trial #1
Identity of metal: _____________________________
__________
Name: _____________________________
Section: ________
Post-Lab Questions
Note: For this and future post-labs, you must show your work on calculation-based problems (using
proper significant figures) for full credit.
1. Do your results verify that density is an intensive property? Explain.
2. Determine whether each of the errors described would cause your calculated density to be incorrectly
high, incorrectly low, or would have no effect. In each case, explain your answer.
a) In Part I, the balance wasn’t properly calibrated and the measured masses were 0.60 g too high.
b) In Part II, instead of sliding the rubber stopper down the graduated cylinder, it was simply dropped
straight down, causing some of the water to splash out.
3. A 500.0mL glass bottle containing 455.0 mL of liquid water (d = 0.9999 g/mL) was sealed and placed in
the freezer, where all the water turned to ice (d = 0.9168 g/mL). Determine whether or not the bottle will
burst.
4. A carbon nucleus has a volume of approximately 8.69 x 10 -39 mL and the molar mass of carbon is 12.01
grams per mole (as we’ll learn in Ch. 4, 1 mole C = 6.02 x 1023 C atoms). Knowing that most of an atom’s
mass in the nucleus, use this information to calculate the density of a carbon nucleus.
Name: _____________________________
Section: ________
Pre-Lab Questions
Note: For this and future pre-labs, you must show your work on calculation-based problems (using
proper significant figures) for full credit.
1. Describe the two methods that will be used for determining the density of a solid in this lab.
2. A 12.2 mL sample of liquid was found to have a mass of 10.4 g.
a) Calculate the density of this liquid (in g/mL).
b) If the same volume of liquid had been chloroform (d = 1.48 g/mL), what would have been the mass of
this sample?
3. A metal weighing 7.101 g is placed in a graduated cylinder containing 33.0 mL of water. The water
level rose to the 37.4 mL mark.
a) Calculate the density of the metal (in g/mL).
b) If you were to do this with an equal mass of aluminum (d = 2.7 g/mL), how high would the water rise?
4. Why would water displacement be the preferred method for determining volume, even if the object were
regularly shaped (cube, cylinder, etc.).