Experiment-3: Density
 To determine density of water from Mass vs. Volume graph.
 To determine density on an unknown liquid.
 To determine density of a solid, using displacement method.
 To determine density of an unknown rectangular metal.
 To determine the thickness of Aluminum foil.
Density is a physical property. It is defined as the mass per unit volume. Density is a
number that relates the mass of matter to the space it takes up. Some types of matter are
more "tightly packed" than others, and therefore have higher densities. All forms of
matter--solids, liquids and gases–have densities. Density is a useful physical property for
identifying and classifying materials. To determine density of a sample, one needs its
exact mass and exact volume. Use the following formula to calculate density:
Density = Mass/ Volume (D=M/V)
It is important to use proper units for the calculated density value. For solids, the units are
g/cc or g/cm3 (gram per cubic centimeters), for liquids, g/mL (grams per milliliter), and
for gases g/L (grams per liter).
Mass can be easily determined using a scale (balance). Volume of a liquid can be found
using a graduated cylinder. Volume of a solid can be found using a displacement method
or may be calculated using a mathematical formula if dimensions of solid are known. It
has been observed that density of solids is greater than the density of liquids and gases
have lowest values. There are few exceptions. Can you think of one?
Density is temperature dependent because Volume is temperature dependent. At higher
temperature the Volume would be greater therefore Density value would be lower.
Conversely, T , V , and D .
It required that proper number of significant figures be used in every calculation!
The volume of a rectangular solid can be found by multiplying the length by width and
then by the height.
Procedure:
Part A, to determine density of water from Mass vs. Volume graph.
1. Obtain a clean and DRY 50-mL or 100-mL beaker. Find the exact mass of this
beaker. Record all the digits. Use this scale throughout this experiment. You mar
record your observations/data on this page then neatly transfer to your lab report.
2. Using a small graduated cylinder, transfer exact 10.0 mL of water into beaker.
Make sure there are no bubbles in the water and you are reading the lowest level
of meniscus. A dropper can be used to adjust the water level in the cylinder.
3.
Using the same scale, find the exact mass of ‘beaker and 10.0 mL water’.
4. Now, using the same small graduated cylinder, transfer exact 10.0 mL of water
into same beaker. Total volume in the beaker at this stage is 20.0 mL.
5. Using the same scale, find the exact mass of ‘beaker and 20.0 mL water’.
6. Now, using the same small graduated cylinder, transfer exact 10.0 mL of water
into same beaker. Total volume in the beaker at this stage is 30.0 mL.
7. Using the same scale, find the exact mass of ‘beaker and 30.0 mL water’.
8. Now, using the same small graduated cylinder, transfer exact 10.0 mL of water
into same beaker. Total volume in the beaker at this stage is 40.0 mL.
9. Using the same scale, find the exact mass of ‘beaker and 40.0 mL water’.
Part B, to determine density of an unknown liquid.
10. Record the unknown liquid sample number._____________.
11. Obtain a clean and DRY 10-mL graduated cylinder. Find its exact mass.
12. Carefully transfer exact 10.0 mL of unknown liquid into 10-mL graduated
cylinder. You are reading the lowest level of meniscus..
13. Find the exact mass of ‘the graduated cylinder and 10.0 mL unknown liquid’.
Discard unknown liquid into regular sink.
Part C, to determine density of a solid, using displacement method.
14. Find exact mass of two ‘Black rubber stoppers #-00’.
15. Obtain a clean 50-mL graduated cylinder and pour water to reach 25.0 mL mark.
Tilt this graduated cylinder and slowly slide both stoppers into this graduated
cylinder. Record the new volume, which is equal to 25.0 mL plus the volume of
two ‘Black rubber stoppers #-00’.
16. Drain the water into sink and replace both ‘Black rubber stoppers #-00’
Part D, to determine density of an unknown rectangular metal
17. Record the unknown rectangular metal sample number._____________.
18. Find exact mass of unknown rectangular metal sample.
19. Find the Length, Width, and Height of unknown rectangular metal in cm.
20. Replace the unknown rectangular metal.
Part E, to determine the thickness of Aluminum foil
21. Obtain a rectangular piece of Aluminum foil. Measure its length and width in cm.
22. Find the exact mass of rectangular piece of Aluminum foil.
23. Replace the rectangular piece of Aluminum foil.
Example, Slope = m = (y2 - y1) / (x2 - x1) = (2 - 1) / (4 - 2) = 1/2
Make a graph with mL liquid on the x-axis (horizontal) and grams liquid one the y-axis
(vertical). Draw the best straight line through the 4 points and (0,0) (use a ruler). You
may use Microsoft Excel or a cm graph paper. Attach the graph to your lab report.
Laboratory Report#3: Density
Last Name_____________________________, first name________________
Date of Experiment___________ Instructor’s Initials_______
Data and Calculations
Part-A, density of water
1. Mass of a DRY 50-mL or 100-mL beaker
=_____________________g
2. Mass of the beaker plus 10.0 mL water
=_____________________g
3. Mass of the beaker plus 20.0 mL water
=_____________________g
4. Mass of the beaker plus 30.0 mL water
=_____________________g
5. Mass of the beaker plus 40.0 mL water
=_____________________g
6. Mass of 10.0 mL water (#2-#1)
=_____________________g
7. Mass of 20.0 mL water (#3-#1)
=_____________________g
8. Mass of 30.0 mL water (#4-#1)
=_____________________g
9. Mass of 40.0 mL water (#5-#1)
=_____________________g
Volume, mL
Mass, g From step 6 – 9
x-axis (horizontal) y-axis (vertical)
0.0
0.00
10.0
Step 6 =
20.0
Step 7 =
30.0
Step 8 =
40.0
Step 9 =
Make a graph (cm) with mL liquid on the x-axis (horizontal) and grams liquid one the
y-axis (vertical). Draw the best straight line through the 4 points and (0,0) (use a
ruler). You may use Microsoft Excel. Attach the graph this lab report.
Part-B, Unknown liquid Number__________
10. Mass of a DRY 10-mL graduated cylinder
=_____________________g
11. Mass of the graduated cylinder and 10.0 mL unknown liquid =______________g
12. Mass of 10.0 mL unknown liquid = (#11- #10) =_____________________g
13. Density of Unknown Liquid = Mass/ Volume = #12 / 10.0 mL= _________ g/mL
Part-C, density of Black Rubber Stoppers
14. Mass of mass of two ‘Black rubber stoppers #-00’ =_____________________g
15. Volume of two ‘Black rubber stoppers #-00’ (step-15) =__________________cc
16. Density of ‘Black rubber stoppers #-00’ = #14/#15 =_________________ g/ cc
Part-D, density of unknown rectangular metal no. __________________
17. Mass of unknown rectangular metal
=_____________________g
18. Volume of unknown rectangular metal = (LxWxH) = _______________cm3
19. Density of unknown rectangular metal = #17/#18
= ____________ g/cm3
Part-E, thickness of Aluminum foil
20. Length of rectangular piece of Aluminum foil
= ___________ cm
21. Width of rectangular piece of Aluminum foil
= ___________ cm
22. Mass of rectangular piece of Aluminum foil
= __________________ g
23. Density of Aluminum foil, given
= 2.70 cm/cm3
24. Volume of Aluminum foil = Mass/Density = #22/#23 = ___________ cm3
25. Thickness of Aluminum foil = Height of Aluminum foil = [V / (L XW)]
= [#24/ (#20 x #21)] = _____________ cm
Show all your work! Use proper units and significant figures!!
1.
A piece of metal weighs 44.867 g. When the metal is lowered into 25.0 mL of
water in graduated cylinder, the level rises to 28.5 mL. Calculate the density of metal.
2.
A solid cube, 2.2 cm on an edge weighed 6.488 grams. Calculate the density of
this cube. Will it sink or float in water? Explain.
3.
Alcohol has a density of 0.79 g/mL. What is the volume of 22.036 g alcohol?
4. A tin foil has a mass of 0.822 g and measures 10.5 cm by 4.50 cm. Calculate the
thickness of this tin foil, given that the density of tin is 7.28 g/cm3.