Density
Density is the mass of a substance per unit of volume. The most common units of measure for
density are ___________ for solids and gasses, and ________________ for liquids.
If you compare two substances with the same volume, the one that has a larger mass (the heavier
one) will be __________dense, since there is more mass packed into the same amount of space.
If you compare two substances with the same mass, then the one that has the smaller volume will
be _________ dense, since you are packing the same mass into a smaller amount of space.
If two substances are mixed, the one with the __________density will stay on top or float.
The density of a material helps to distinguish it from other materials. Some common densities
are given below:
Density Table
Solids (g/cm3)
Gold
Silver
Aluminum
Wood (birch)
Wood (cedar)
Cork
19.3
10.5
2.7
0.66
0.37
0.25
Liquids (g/mL)
Mercury
Sea water
Water
Olive oil
Rubbing alcohol
Gasoline
13.6
1.03
1.00
0.92
0.79
0.69
Density can be calculated using the following formula:
Density =
The formula can be rearranged to solve for mass and volume:
Mass =
Volume =
Problems
1. A necklace has a mass of 15.4 g and a volume of 0.8 cm3. Calculate the density of the
necklace, and then use the information in the box above to determine the type of metal in
the necklace. Use the GUESS method.
Given:
Equation:
Solve:
Unknown:
Sentence:
2. Nickel has a density of 8900 kg/m3. Find the volume occupied by 31000 kg of nickel.
DENSITY PROBLEMS
Answer all questions on a separate sheet of paper, and show all your work.
1. If you have a mineral sample with a volume of 4 mL and a mass of 20 grams, what is the density?
2. An object has a mass of 7 grams and a total volume of 18 mL. What is the density of this object? Will it
sink or float in water? Note: the density of water is 1.0 g/mL
3. Gasoline has a density of 0.69 g/mL. What is the mass of 1000 mL of gasoline?
4. A block of dimensions 4 cm by 3 cm by 2 cm has a mass of 8.88 g. Calculate its density and use the
density table (on the front of this sheet) to identify the substance.
Remember: Volume = length x width x height
5. A beaker has a mass of 200 g. If 50 mL of a liquid is poured into the beaker, the total mass of beaker and
liquid is 239.5 g. What is the density of the liquid? Identify the liquid.
6. Iron has a density of 7.9 g/cm3. If an iron nail has a mass of 1.2 g, then what is the volume of the nail?
7. Ethyl alcohol has a density of 0.8 g/mL. Would a 100 mL graduated cylinder hold 120 g of ethyl alcohol?
8. A piece of nickel has a mass of 130 g and a density of 8.9 g/cm3. A piece of magnesium has a mass of 60g
and a density of 1.6 g/cm3. Which piece of metal will displace more water from an overflow can?
9. Use the density table on the front of this sheet to help you answer the following questions.
a) A prospector finds a piece of metal, which has a mass of 100 g and a volume of 20 cm3. Is the metal
gold?
b) A block of aluminum and a block of silver both have the same mass. Which would have the largest
volume? Explain.
c) A bottle of water and a bottle of rubbing alcohol both have the same volume. Which would have the
largest mass? Explain.
10. The case of the missing crown: Imagine that you are living in Europe in the Middle Ages. You have been
summoned by the King of your land to help in a very important matter. Someone has stolen the King’s
solid gold crown. The King has issued a proclamation offering a reward of 500 gold coins for the safe
return of his crown. The problem is that the King has received hundreds of crowns – and they all look
exactly like the missing crown! Your job as a brilliant scientist is to find out which crown is the real one.
The chart below shows some data that you have collected on one batch of crowns. Study the data, then
answer the questions.
Crown #
1
Volume (cm3)
180
Mass (g)
1890
2
180
486
3
180
1404
4
180
3474
5
180
2034
Density (g/cm3)
a) In the space provided to the right of the data, calculate the densities of the 5 crowns.
b) Based on your calculations, do you think that any of these crowns could be the real one? Why or why
not? (Hint: Look up the density for gold in the density table on the front of this sheet).
c) Which of these crowns do you think are fakes? Why?
Density Problems
Answer the following questions on another piece of paper. Show your work.
1) If you have a mineral sample with a volume of 4 ml and a mass of 20 grams, what is the
density?
2) If you have a mineral sample with a volume of 40 ml and a mass of 200 grams, what is
the density?
3) An object has a mass of 7 grams and a total volume of 18 mL. What is the density of this
object? Will it sink or float in water?
Note: the density of water is 1.0 g/mL.
4) Gold has a density of 19 300 kg/m³. Find the mass of a piece of gold with a volume of
7m³.
5) Iron has a density of 7.9 g/cm3. If an iron nail has a mass of 1.2 g, then what is the
volume of the nail?
6) Ethyl alcohol has a density of 0.8 g/mL. Would a 100 mL graduated cylinder hold 120 g
of ethyl alcohol?
7) A piece of nickel has a mass of 130 g and a density of 8.9 g/cm3. A piece of magnesium
has a mass of 60 g and a density of 1.6 g/cm3. Which piece of metal will displace more
water from an overflow can?
8) You find a piece of an unknown metal in the lab. You measure its mass and find it to be
6.2 g. You measure its volume and find it to be 0.55 cm3. What type of metal is it
(compare this metal’s density to the densities of metals on the front of this sheet).
9) If you had a 10 g piece of each of the substances in the table below, then which substance
would