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DENSITY of SOLIDS and LIQUIDS LAB
WEEK I and WEEK II
NOTE: WEEK I write-up will include all sections of the formal lab report.
WEEK II write-up will only include data, graphs, calculations and post lab for WEEK II stations.
PRELAB
Read the lab and answer the following questions on a separate sheet of paper. Use complete
sentences or show mathematical calculations showing work, units, and significant figures.
1. Find the equations that you would use to calculate the volume of a cube, a rectangular
solid, a cylinder, and a sphere (hint-consult your planner or math text).
2. True or False – A ton of steel will have a larger density than 1 steel nail.
3. Read the volume on each of the graduated cylinder pictures shown in the background
section and then determine the volume of the object that was submerged in the cylinder to
make the water level rise. Report your answer to the proper number of decimal places/
significant figures. Label them Vcylinder and Vring.
4. Use the terms inversely or directly to complete the following:
Mass and density are __________________proportional. Volume and density are
__________________proportional.
5. Research the following substances: sintra, PVC, PP, acrylic, and HDPE. Record their full
names, chemical formulas, and density values (or range of density values). What do the
substances have in common?
6. Why are the theoretical density values of brass, bronze, and steel reported as a range of
densities? How can you categorize these substances? (use terms from your chapter one
notes)
OBJECTIVE
1. To find the density of a metal cube, a rectangular solid, and a liquid sample and to use the
density to identify the substance.
2. To use water displacement to determine the volume of an irregular shaped object and to
use that volume to calculate density.
3. To graphically analyze mass and volume to determine the density of a sample of brass.
4. To use density to determine the % composition of pennies.
5. To determine the thickness of a piece of aluminum metal.
6. To analyze data using average, average deviation, and percent error calculations.
BACKGROUND
Matter can be described qualitatively through observation of intensive or extensive physical or
chemical properties. This lab will explore the extensive properties of mass and volume and their
relationship to the intensive property, density. Recall that mass is a measure of how much matter
is in a substance. The standard unit for measuring mass is the kilogram; however, our lab
balances are calibrated using grams. Volume is a measurement of the amount of space occupied
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by a sample of matter. Volume is measured in units of cm3 or ml. When mass is divided by
volume, the result is the density of the substance.
DENSITY =
MASS
VOLUME
The resulting units of density are g/cm3 or g/ml. The obtained density value may be used to
identify an unknown sample by comparing it to a chart of known (theoretical) density values. You
could find such a chart in your textbook or in the CRC Handbook of Chemistry and Physics.
Possible identities of substances used in this lab include: aluminum, zinc, copper, cadmium, tin,
lead, bronze, brass, steel, PP, Sintra, PVC, acrylic, HDPE, ethanol, ethylene glycol, corn oil,
glycerol, or water.
This lab will employ two techniques to determine the volume of objects. One technique involves
measurements of the dimensions of the object and using mathematical relationships to find the
volume of regular shaped objects. This method assumes that the object is solid and free of air
space. If, however, the solid is irregularly shaped or contains air space between particles, it is
necessary to perform water displacement to find the volume. This method begins with a known
volume of water in a graduated cylinder. Then the object is placed into the water and the new
volume is recorded. The difference in the recorded water volumes must equal the volume of the
object submerged in the water. In order for water displacement to work, the object must be
completely submerged in the water and must not be soluble or able to chemically react with the
water.
Here are two sample graduated cylinder before and after the object is submerged. The volume of
the water should be read to 1 decimal place (1 digit beyond the markings on the cylinder). The
last digit is an estimated digit which adds some amount of uncertainty to the volume reading.
This uncertainty may lead to errors in your density calculations.
Luckily, determining the mass of each sample is quite easy. You will use the electronic balance
and record the masses to the second decimal place.
MATERIALS
Electronic balance
Weighing dish
Calipers
Ruler
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100 ml graduated cylinder (plastic, so that it
does not shatter when the sample is
introduced)
Pipette(s)
Cubic metal samples
Rectangular solid samples
Irregular shaped solids samples
Pennies
Aluminum foil
Unknown liquid samples
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PROCEDURES
The following parts may be completed in any order.
WEEK I
PART I: CUBIC SOLIDS
1. Obtain a metal cube and make qualitative observations.
2. Find the mass of your cube.
3. Determine the average length of a side of the cube.
4. Return the cube to its storage box.
5. Perform calculations of volume, density, and percent error. Identify the metal sample and
determine the % error of your result.
PART II: RECTANGULAR SOLIDS
1. Obtain a rectangular solid and record its ID number as well as qualitative observations.
2. Find the mass of the solid.
3. Determine the length, width, and height of the solid.
4. Return the rectangular solid to its storage box.
5. Perform calculations of volume, density, and percent error. Identify the rectangular solid
sample and determine the % error of your result.
PART III: IRREGULAR SHAPED OBJECT
1. Obtain and irregular shaped metal object and record qualitative observations.
2. Record the mass of the object.
3. Determine the volume of the object through water displacement. Fill a 100 ml graduated
cylinder to approximately the 50 ml mark. Record the exact volume to 1 decimal place.
Carefully place the metal sample into the cylinder and record the new volume of the water.
4. Dry your metal sample and return it to its storage box.
5. Share your data with another group that used the same metal sample.
6. Perform calculations of volume, density, percent error, average deviation, and a precision
check. Identify the irregular solid sample and determine the % error of your result.
WEEK II
PART I: DENSITY of BRASS
1. Obtain five brass cylinders and record qualitative observations.
2. Record the mass of each cylinder.
3. Record the length and diameter of each cylinder using the Vernier calipers.
4. Return the cylinders to their storage box.
5. Perform calculations to determine the volume of each.
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6. Create a graph of mass vs. volume for the five cylinders. Include two titles, axes labels and
units, data points connected by a line and show a slope calculation after determine the line of
best fit through the points. The slope represents the density of brass.
7. Calculate % error.
8. Given the density of copper and zinc, determine the % of each element combined to make the
alloy, brass.
PART V: % COMPOSITION of PENNIES
1. Obtain 10 pennies making sure that they are all post 1982.
2. Record the mass of the 10 pennies all at once. Determine the average mass of one penny.
3. Use water displacement to find the volume of all 10 pennies together. Determine the average
volume of one penny.
4. Calculate the density of the pennies using the mass of all 10/ volume of all 10 and also using
the average mass of 1 penny/ average volume of 1 penny.
5. Determine the % of the penny (post 1982) that is actually copper and zinc given the fact that
the inner core of the penny is zinc.
PART VI: LIQUID DENSITIES
1. Select one of the four mystery liquids to identify. Record its letter and qualitative observations.
2. Weigh three empty pipets. Find the average mass of an empty pipet.
3. Use the pipet in the container of liquid and draw up 1.0 ml of solution to the line right below the
bulb of the pipet. Quickly release the pressure on the bulb and invert the pipet so that the
liquid flows into the bulb end. Carefully clean the exterior of the pipet. Find the mass of the
pipet and liquid by placing the filled pipet in a weighing dish (that has been tared) on the
electronic balance. Repeat finding the mass three times with the same liquid.
4. Calculate the average mass of the liquid, the average density, compare the density to the
theoretical values and determine the identity of the mystery liquid. Report your percent error,
average deviation, and precision check.
PART VII: THICKNESS of ALUMINUM
1. Obtain a piece of aluminum foil.
2. Write a procedure that will allow you to determine the thickness of the piece of foil. Your
procedure should involve density and should not use calipers.
3. Carry out the procedure and report your results in a data table that you design.
4. Consider averaging your data with other groups to validate your results.
DATA
WEEK I
PART I: CUBIC SOLIDS
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QL observations of the
metal:
Calculation
(show only when necessary)
Value and Unit
Mass of cube
Length of side
Volume of cube
Density (experimental)
Possible identity of
metal
Theoretical density
% error
PART II: RECTANGULAR SOLIDS
ID #
QL observations of the
rectangular solid:
Calculation
(show only when necessary)
Value and Unit
Mass of solid
Length
Width
Height
Volume of rectangular
solid
Density (experimental)
Possible identity of solid
Theoretical density
% error
PART III: IRREGULAR SHAPED OBJECT
QL observations of the
metal:
Calculation
(show only when necessary)
Mass of irregular object
Final volume of water after
object is submerged
Value and Unit
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Initial volume of water
Total volume of water
displaced = volume of the
irregular object
Density (experimental)
Density data from other
groups:
Initial each data set
Possible identity of metal
Group 1
Group 2
Group 3
Theoretical density
Average density:
Compare 4 trials
% error
Compare average to
theoretical
Average deviation
Compare 4 trials
Precision check
Compare 4 trials
WEEK II
PART IV: DENSITY of BRASS
QL observations of the cylinders:
Cylinder #
1
2
3
4
5
Attach a full sheet graph of mass
vs. volume.
Density of brass from graph:
mass
Slope calculation:
length
Radius
volume
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% error
(given average theoretical density
of 8.00 g/ml)
% copper and % zinc in the brass
sample. Show a weighted
average calculation.
PART V: % COMPOSITION of PENNIES
Calculation
(only show when necessary)
Value and unit
Mass of all 10 pennies at once
Volume of 10 pennies at once
Density using mass and volume
of 10 penny data
Average mass of 1 penny
Average volume of 1 penny
Density using average mass
and volume of 1 penny
Theoretical density of a post
1982 penny
% error of penny density
% of copper and % zinc in the
penny (show work using a
weighted average)
PART VI: LIQUID DENSITIES
Liquid letter ID:
QL observations of liquid
sample:
Mass of empty pipet
Average mass of empty pipet
Mass of pipet and liquid
Mass of liquid
Volume of liquid inside pipet
Density of liquid
Average density of liquid
Possible identity of liquid
Theoretical density of liquid
Percent error
Calculations (show when necessary)
1.
2.
3.
Value and unit
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Average deviation
Precision check
PART VII: THICKNESS of ALUMINUM
You design the data table. The final copy should be typed.
POST LAB QUESTIONS
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2.
3.
4.
5.
WEEK I
A cylinder of lead has a radius of 2.6 cm and a height of 12 cm. What is the mass of this piece
of lead?
A cube of aluminum has a mass of 25.50 grams. Determine the dimensions of the cube.
A rectangular block has dimensions: 4.5 cm x 1.7 cm x 7.8 cm. The mass of the block is 312
grams. Based upon this, will this block float or sink in water?
A cylindrical tin can has a height of 22.00 cm, an external radius of 5.00 cm and an internal
radius of 4.99 cm (assume the tin has the same thickness at the sides and on its base and
assume an open container). Given the density of tin = 2.8 g/cm 3, determine the mass of the
empty tin can. If the can is filled with water, calculate the mass that would appear when the
filled can is placed on the electronic balance.
The density of petroleum oil is less than the density of sea water. Explain how this fact will
help in an oil spill cleanup.
POST LAB QUESTIONS
WEEK II
1. An alloy of bronze was made by combining 88 % copper and the rest is composed of tin.
Determine the density of the bronze sample using a weighted average.
2. Would it be possible to calculate the volume of a sample of calcium metal using water
displacement? Explain.
3. Why did the pennies all have to be post 1982? Would the density have been higher or lower
given pre-1982 pennies?
4. Compare the density of pennies calculated with one penny versus the density calculated with
all ten pennies. Explain your findings. Why did the procedure call for you to find the mass
and volume of 10 pennies at a time instead of 1 at a time?
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5. Given the % of copper that you found in the post 1982 pennies and given your total mass of
pennies, what is the true value of the copper in the ten pennies? Show a calculation. (hint –
find the current scrap value of copper).
6. When reporting density of gases, what is the most appropriate unit?
7. The Hindenberg Zepplin airship was filled with hydrogen gas. Given the volume 7,062,000 ft 3,
determine the mass of hydrogen gas that would be needed to fill the balloon. The balloon was
originally engineered to be filled with He. What is the mass of He gas required to fill the
balloon? Why was the balloon filled with hydrogen instead of He?