DETERMINATION OF
The DENSITY of LIQUIDS & SOLIDS
Density of a substance is its mass per unit volume
density = mass/volume
Density (solid) can be determined by weighing solid &
then measuring the volume it occupies.
Volume can be determined by:
measuring the dimensions of the solid and calculating
its volume, or by
measuring the volume of liquid that is displaced by the
solid.
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Density Connections
Mass
Volume
kg
L
g
mL (cm3)
mg
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Density =
Mass
Volume
Solids & Liquids g/mL
Gases g/L
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Volume – SI derived unit for volume is cubic meter (m3)
1 cm3 = (1 x 10-2 m)3 = 1 x 10-6 m3
1 dm3 = (1 x 10-1 m)3 = 1 x 10-3 m3
1 L = 1000 mL = 1000 cm3 = 1 dm3
1 mL = 1 cm3
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1.7
EXPERIMENTAL PROCEDURE
I. Determination of the density of a regular solid
Unknown solid, vernier caliper
Record the number of the unknown,
Weigh the solid on the electric balance.
Measure the solid dimensions (length
diameter), using the calipers
 Calculate the volume of the solid
 Calculate the density of the unknown solid.




and
 If the density from the second trial is
approximately the same as the first trial (within 1 %),
calculate the average density.
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 If the second number differs greatly from the
first one, do the
experiment a third time.
Calculate the average of the two best results.
D =
mass
volume
= g
mL
or
g
cm3
Note: 1 mL = 1 cm3
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© Instructor : Mrs. Mona Kanj EL-Harakeh 
Unknown Cubic
Solid
Trial 1
Trail 2
Mass of solid
Precision
Length
Precision
Width
Precision
Height
Precision
Volume of solid
(Calculated)
L*W*H
L*W*H
Density of solid
D1
D2
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Average
density
± 0.0001g
± 0.0001g
± 0.002cm
± 0.002cm
± 0.002cm
± 0.002cm
± 0.002cm
± 0.002cm
Kanj
D = DMona
+D
1
2/ 2
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Reading
Vernier Caliper
 Read the centimeter mark on the fixed scale to the
left of the 0-mark on the vernier scale. (2 cm on
caliper seen above)
 Find the mm mark on the fixed scale that is just to
the left of the 0-mark on the vernier scale. (2.6 cm)
 Look along the ten marks on the vernier scale and
the millimeter marks on the adjacent fixed scale, until
you find the two that most nearly line up. (0.04cm)
 To get the correct reading, simply add this found
digit to your previous reading.
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 Reading: 2.64
The Vernier caliper is a versatile
tool.
 It can measure the outside
diameter or width of an object.
It can measure the inside diameter
or width of an object.
It can measure the depth of an
object.
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2.13
2.00
2.34
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reading is 3.47
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II.Determination of the density of an irregular solid
 Unknown solid of irregular shape. Record the kind
of the unknown.
 Weigh the solid on the electric balance.
 Pour distilled water into a 50 ml graduated cylinder
to approximately the 15-ml mark.
Read the level of the water accurately to the nearest
± 0.5 ml
 Be careful not to let the solid hit the bottom too
hard, it might break the glass.
 avoid having air bubbles trapped by the solid.
 Read the new level of the water
 Determine the volume of the solid by subtracting
the water level readings before and after the solid was
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placed
 Calculate the density of the unknown irregular solid.
 Repeat the above procedures (II-1) through (II-4),
after drying the irregular solid with a paper towel.
 If the density from the second trial is approximately
the same as the first one (within 1 %), calculate the
average density.
 If the second number differs greatly from the first
one, repeat the experiment for a third time. Reject the
density that differs most from the other two. Calculate
the average of the best two results.
 Return the unknown to the instructor.
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Volume Displacement
• A solid displaces a matching volume of water when
the solid is placed in water.
15ml
H2O
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26.5 ml
H2O
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III. Determination of the density of an unknown liquid
Obtain an unknown liquid from your instructor.
Record the number of the unknown and all
measurements and calculations on the Report Sheet.
 Clean a 10-ml volumetric flask with acetone inside
the fume hood and leave it for five minutes to dry.
Dispose of the acetone in the waste bottle in the hood.
 Weigh the dry volumetric flask (with stopper).
 Rinse the volumetric flask with 3 or 4 ml of the
unknown liquid, and discard the rinse liquid into the
"waste" beaker in the fume hood.
 Fill the volumetric flask with the unknown liquid
exactly up to the mark.
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Weigh both the stoppered flask and the liquid
together.
 Calculate the density of the unknown liquid, and
discard the unknown liquid into the waste bottle in
the fume hood.
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Density (liquid) is determined by weighing a known
volume of the liquid.
density = mass/volume
A volumetric flask is a glass container, which holds a
defined volume of liquid. The mass of the liquid is
determined by weighing the volumetric flask first empty
and then full of the liquid. The density can be calculated
from the mass and volume.
Volume of a liquid changes with its temperature, it is
necessary to keep a record of the temperature at which
densities are measured.
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Unknown
Irregular Solid
Mass of solid
Precision
Volume of water
without solid
Precision
Volume of water with
solid
Precision
Volume of solid
Density of solid
Average density
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Trial 1
Trail 2
± 0.0001g
± 0.0001g
± ml
±
ml
± ml
±
ml
D1
D2
D = D1 +D2 / 2
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Unknown Liquid
Trial 1
Mass of flask + stopper
Precision
± 0.0001 g
Mass of flask + stopper +
liquid
Precision
± 0.0001 g
Mass of liquid
Volume of liquid
Precision
Density of liquid (with
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correct
±
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