1. The document discusses density and how it is calculated for different materials and objects. Density is defined as mass per unit volume. Examples are given for calculating density of regular solids, irregular solids, liquids, and gases by measuring mass and volume. 2. Several word problems are provided as examples of calculating density given the mass and volume of an object or substance.

1. DensityDensity Modified byModified by
CHAIPORN PATTANAJAKCHAIPORN PATTANAJAK
Banphue pittayasan schoolBanphue pittayasan school
Facebook.com/chaiporn.pattanajak

2. State of MatterState of Matter
Solid is fixed shape
Liquid takes on the shape of
its container.
Gas has neither a fixed shape
nor a fixed volume
Recall

3. DENSITYDENSITY
Q) Which weighs more:-
A kilogram of feathers or a kilogram of iron?

4. What is Density?What is Density?
Density is the Mass per unit
Volume
Wood Water Iron
1 cm3
1 cm3 1 cm3
If you take the same volume of different substances,
then they will weigh different amounts.
0.50 g 1.00 g 8.00 g
Q) Which has the greatest mass and therefore the most dense?
IRON

5. Density =
Mass
Volume
g or kg
cm3
or m3gcm-3
or kgm-3 ρ = m
VExample:
Q) Liquid water has a density of 1000kgm-3
, while ice has density
of 920kgm-3
. Calculate the volume occupied by 0.25kg of each.
Density Equation:
m
Vρ
V = m = 0.25 = 0.000250m3
ρ 1000
V = m = 0.25 = 0.000272m3
ρ 920

6. DENSITY OF A REGULAR SOLIDDENSITY OF A REGULAR SOLID
 Find the Mass ofFind the Mass of
the solid on athe solid on a
balance.balance.
 Measure theMeasure the
three lengths andthree lengths and
calculate thecalculate the
Volume.Volume.
(ie V = l x w x h )(ie V = l x w x h )
 Calculate theCalculate the
Density.Density.l = 4.0 cm
w= 2.0 cm
h=3.0 cm
ρ = m = 240 =10.0 g/cm3
V 24
m = 240 g

7. DENSITYDENSITY g/cmg/cm33
AluminiumAluminium 2.702.70
BrassBrass 8.508.50
IronIron 7.867.86
WoodWood 0.500.50
SlateSlate 2.802.80
GlassGlass 2.502.50
LeadLead 11.311.3
MarbleMarble 2.702.70
WaxWax 0.890.89

8. DENSITY OF AN IRREGULAR SOLIDDENSITY OF AN IRREGULAR SOLID
 Find the Mass of the solidFind the Mass of the solid
on a balance.on a balance.
Fill the Measuring CylinderFill the Measuring Cylinder
with Water to a knownwith Water to a known
Volume.Volume.
 Add the Object.Add the Object.
 Work out the Volume ofWork out the Volume of
Water that is displaced.Water that is displaced.
 Calculate the Density.Calculate the Density.
50 cm3
80 cm3
m = 360 g
ρ = m = 360 =12.0 g/cm3
V 30

9. DENSITY OF AN IRREGULAR SOLIDDENSITY OF AN IRREGULAR SOLID
 OR use a Eureka Can to find the Volume.OR use a Eureka Can to find the Volume.
 Find the mass of the solid onFind the mass of the solid on
a balance.a balance.
Add water until justAdd water until just
overflowing.overflowing.
 Place a Measuring CylinderPlace a Measuring Cylinder
under the spout.under the spout.
 Add the Object.Add the Object.
 Collect the Water and read offCollect the Water and read off
the Volume.the Volume.
Calculate DensityCalculate Density
m = 440 g
40.0 cm3
ρ = m = 440 =11.0 g/cm3
V 40

10. DENSITY OF A LIQUIDDENSITY OF A LIQUID
 Find the Mass of an emptyFind the Mass of an empty
Measuring Cylinder.Measuring Cylinder.
 Add a certain Volume of Liquid.Add a certain Volume of Liquid.
 Find the Mass of the MeasuringFind the Mass of the Measuring
Cylinder and LiquidCylinder and Liquid
 Calculate the Mass of Liquid.Calculate the Mass of Liquid.
 How?How?
 Calculate Density of Liquid.Calculate Density of Liquid.
Mass of Liquid = Mass of Measuring Cylinder and Liquid – Mass
of
empty Measuring Cylinder
25.0 g
20.0 cm3
45.0 g
45 – 25 = 20 g
ρ = m = 20 =1.00 g/cm3
V 20

11. DENSITY OF A GASDENSITY OF A GAS
 Remove the air fromRemove the air from
a flask of a knowna flask of a known
Volume, using aVolume, using a
vacuum pump.vacuum pump.
 Find its Mass.Find its Mass.
 Add the gas to beAdd the gas to be
tested.tested.
 Reweigh.Reweigh.
 The difference is theThe difference is the
Mass of gas.Mass of gas.
 Calculate Density.Calculate Density.
To vacuum flask
1000 cm3
m(glass)=150.0 g
m(total)=170.0 g
ρ = m = 20 =0.0200 g/cm3
V 1000
170 -150 = 20.0g

12. Problem of DensityProblem of Density
2. What is the density of a piece of
wood that has a mass of 25.0
grams and a volume of 29.4 cm3
?
1. A piece of wood that measures 3.0 cm by 6.0
cm by 4.0 cm has a mass of 80.0 grams.
What is the density of the wood?
Would the piece of wood float in water?
(volume = L x W x H)

13. 3. A cup of gold colored metal beads was3. A cup of gold colored metal beads was
measured to have a mass 425 gramsmeasured to have a mass 425 grams.. By waterBy water
displacement, thedisplacement, the volumevolume of the beads wasof the beads was
calculated to be 48.0 cmcalculated to be 48.0 cm33
.. Given the followingGiven the following
densities, identify the metaldensities, identify the metal..
GoldGold:: 19.3 g19.3 g//mLmL
CopperCopper:: 8.86 g8.86 g//mLmL
BronzeBronze:: 9.87 g9.87 g//mLmL

14. 4. The4. The volumevolume of aof a solutionsolution
was measured in a graduatwas measured in a graduat
eded cylindercylinder (shown above). I(shown above). I
f thef the massmass ofof solutionsolution is meis me
asured to be 60.75 grams,asured to be 60.75 grams,
what is thewhat is the densitydensity of the solof the sol
ution?ution?