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1.0: PROPERTIES OF MATTER
1.2: DENSITY
ENABLING OBJECTIVES:
1. Explain density:
1.1. Define density.
1.2. Solve simple problem on density.
2. Carry out an experiment to differentiate the density of regular and irregular shaped solids
and liquids.
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1.0: PROPERTIES OF MATTER
1.2: DENSITY
DENSITY.
•
Density of a substance is defined as its mass per unit volume.
Density 
mass
volume

m
v
where  = density of a substance
m = mass of the substance
v = volume of the substance
•
S.I. Unit: kgm-3.
•
Other unit: gcm-3.
INVESTIGATING THE DENSITY OF SOLIDS
Regular-shaped solids.
•
The volume of a substance of regular shape (rectangular bar, cylinder or sphere) may be
calculated from measurements made by venier calipers or micrometer screw gauge.
Irregular-shaped solids.
•
The volume of an irregular shape solid (stone) may be determined by using the displacement
method.
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1.0: PROPERTIES OF MATTER
1.2: DENSITY
To determine the density of regular-shaped solid.
Apparatus: Vernier calipers, ruler and electronic balance.
Procedure:
1) Find the mass, m, using the electronic balance.
2) Determine the volume by taking appropriate measurements and then calculating the volume
as follows:
 cuboid – measure the length, breadth and height by using a metre rule or venier
calipers. V  l  b  h

 d 2  

  l 
 cylinder – measure the diameter and the length. V  


4

 

 sphere – measure the diameter with a pair of venier calipers together with a metre
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
4  d  

rule. V    

3  2  

To determine the density of irregular-shaped solid.
Apparatus: Measuring cylinder, thread, irregular-shaped solids.
Procedure:
1) Weigh and record the mass of the irregular-shaped solids.
2) Pour water into the measuring cylinder up to a certain level, e. g. 50 cm3.
3) Place the irregular-shaped solids into the measuring cylinder.
4) Record the new reading on the measuring cylinder.
5) Calculate the densities of each of the irregular-shaped solids.
6) Calculate the densities of each object.
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1.0: PROPERTIES OF MATTER
1.2: DENSITY
INVESTIGATING THE DENSITY OF LIQUIDS
To determine the density of a liquid.
Apparatus: Burette, beaker, balance, retort stand.
Procedure:
1) Find the mass of a clean, dry beaker (m1).
2) Run a volume (V) of the liquid from the burette into the beaker.
3) Find the mass of the beaker and the liquid (m2).
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