Science Lab Sek-Catalunya
Measuring density Lab
1rst ESO
Measuring density
1. Background Information:
All matter has mass and volume. Mass is a measure of the amount of matter an object has. Its measure is
usually given in grams (g) or kilograms (kg). Volume is the amount of space an object occupies. There are
numerous units for volume including liters (l) or meters cubed (m 3)
Mass and volume are physical properties of matter and may vary with different objects.
For
example, it is possible for two pieces of metal to be made out of the same material yet for one piece to be
bigger than the other. If the first piece of metal is twice as large as the second, then you would expect that
this piece is also twice as heavy (or have twice the mass) as the first. If both pieces of metal are made of
the same material the ratio of the mass and volume will be the same.
We define density (  ) as the ratio of the mass of an object to the volume it occupies. The equation

is given by:
M
V
Density has the units of mass divided by volume
Sample problema 1
A block of wood has a mass of 8 g and occupies a volume of 10 cm 3. What is its density?
Solution
The density will be
8g
 0.8 g / cm 3 .
10cm 3
This means that every centimeter cube of this wood will have a mass of 0.8 grams.
Science Lab Sek-Catalunya
Measuring density Lab
1rst ESO
Liquids
Mercury
Glycerine
Milk
Sea Water
Water
Alcohol
Gasoline
Density (g/cm3 )
13.60
1.26
1.03
1.02
1.00
0.79
0.67
Table 1. Density of liquid substances. Densities are in g/cm 3.
2. Purpose: To calculate the density of different liquids.
3. Hypothesis: DO THIS BEFORE YOU BEGIN EXPERIMENTING!!!
4. Materials and apparatus:
o
o
o
o
o
o
o
Water
Oil
Milk
Ethanol
100mL Graduated Cylinder
100ml beaker
Electronic balance
5. Procedure:
a. Measure 10 grams of water.
b. Show your math and record into the data table.
c. Empty Liquids into the beaker.
d. Re-weigh your cylinder after every Trial.
e. Wash and dry your materials after each type of liquid.
f. Repeat from a-e for each liquid
6. Record the volume of water and the other liquids.
7. Using the formula for density, calculate the density of liquids. Show your math on your lab-sheet.
8. Average the density from trial 1 and trial 2. Record under Average Density of Liquid (g/mL).
9. Properly clean your materials and lab stations by pouring your Beaker into the appropriate waste
container.
10. Wash and dry all materials used.
Science Lab Sek-Catalunya
Measuring density Lab
1rst ESO
6. Results and discussion
Liquids
Mass of
Grad. Cyl.
(g)
Mass of
Grad. Cyl.
+ Liquid
(g)
Mass of
Liquid
(g)
Volume of
Liquid
(mL)
Density
(g/mL)
Average
Density of
Liquid
(T1 + T2)/2
Water
Trial 1
Water
Trial 2
Ethanol
Trial 1
Ethanol
Trial 2
Milk Trial 1
Milk Trial 2
Oil Trial 1
Oil Trial 2
Show your Math:
7. Conclusions
8. Post-Lab
1.
2.
3.
4.
5.
6.
7.
Why is it important to wash and dry your graduated cylinder between each liquid?
Explain in your own words what density is:
Fill in the Blanks:
Density is the ____________ per unit volume of a substance.
When a substance has a high density, a large mass fits into a ____________ volume.
The units of __________ are grams per cubic centimeter.
What is the density of a metal block that has a mass of 525g and a volume of 50cm 3?
Remember to properly show your work!
8. What measurements must be known to find the density of a substance?
9. What are the units of density for a liquid?
10. If 5mL of a liquid has a mass of 10g, what is its density? Show your work properly!
11. When you are finding the density of a liquid, why should you find the mass of the container
holding the liquid first?
12. If 30mL of a liquid has a density of 0.67g/mL, what is its mass? Show your work properly!