1. Chapter 1 Measurements 1.7 Density
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

2. Density Density Compares the mass of an object to its volume.
Is the mass of a substance divided by its volume.
Density expression
Density = mass = g or g = g/cm3
volume mL cm3
Note: 1 mL = 1 cm3

3. Densities of Common Substances

4. Learning Check
Osmium is a very dense metal. What is its density in g/cm3 if 50.0 g of osmium has a volume of 2.22 cm3?
1) g/cm3
2) g/cm3
3) g/cm3

5. Solution Given: mass = 50.0 g volume = 22.2 cm3
Plan: Place the mass and volume of the osmium metal
in the density expression.
D = mass = g
volume cm3
calculator = g/cm3
final answer (2) = g/cm3

6. Volume by Displacement
A solid completely submerged in water displaces its own volume of water.
The volume of the solid is calculated from the volume difference.
45.0 mL mL
= 9.5 mL = 9.5 cm3
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

7. Density Using Volume Displacement
The density of the zinc object is
then calculated from its mass
and volume.
mass = g = 7.2 g/cm3 volume cm3
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

8. Learning Check
What is the density (g/cm3) of 48.0 g of a metal if the level of water in a graduated cylinder rises from 25.0 mL to 33.0 mL after the metal is added?
1) g/cm3 2) 6.0 g/cm3 3) 380 g/cm3
33.0 mL
25.0 mL
object

9. Solution Given: 48.0 g Volume of water = 25.0 mL
Volume of water + metal = 33.0 mL
Need: Density (g/mL)
Plan: Calculate the volume difference. Change to cm3,
and place in density expression.
33.0 mL mL = mL
8.0 mL x 1 cm3 = cm3
1 mL
Set up Problem:
Density = g = g = 6.0 g/cm3
8.0 cm cm3

10. Sink or Float
Ice floats in water because the density of ice is less than the density of water.
Aluminum sinks because its density is greater than the density of water.
Copyright © by Pearson Education, Inc.
Publishing as Benjamin Cummings

11. Liquid Layers
If you pour together liquids that don’t mix and have different densities, they will form liquid layers.
The liquid with the highest density will be on the bottom.
The liquid with the lowest density will be on the top.

12. Learning Check
Which diagram correctly represents the liquid layers in the cylinder? Karo (K) syrup (1.4 g/mL), vegetable (V) oil (0.91 g/mL,) water (W) (1.0 g/mL) K W V V W K V W K

13. Solution vegetable oil 0.91 g/mL V W K 1) water 1.0 g/mL
Karo syrup 1.4 g/mL V W K

14. Liquid Layers
Check out this picture from your book. Which layer has the highest density?
Which layer has the lowest density?
Imagine that the liquids have the following densities:
10g/cm3. 3g/cm3.
6g/cm3. 5g/cm3.
Which number would go with which layer?

15. Liquid Layers – Try with your neighbor
Which liquid has the highest density?
Which liquid has the lowest density?
Which liquid has the middle density?

16. Liquid Layers – Try on your own!
Imagine that the liquids on the right have the following densities:
15g/cm g/cm3
3g/cm g/cm3
7g/cm g/cm3
Match the colors to the correct densities.
3g/cm3
7g/cm3
9g/cm3
10g/cm3
12g/cm3
15g/cm3