Density
Density is an INTENSIVE property of matter.
Ratio of mass (normally g or kg) to volume
(normally cm3 or m3) = g/cm3 or kg/m3
•
- does NOT depend
on quantity of
matter.
•
Contrast with
EXTENSIVE property
- depends on
quantity of matter.
- mass and volume
Styrofoam
Brick
It appears that the brick is ~40x
more dense than the styrofoam.
Styrofoam
?
Brick
Density of Some
Common Substance
Substance
Density of Some Common Substances
Density
(g / cm3)
Air
Lithium
Ice
Water
Aluminum
Iron
Lead
Gold
*at 0oC and 1 atm pressure
0.0013*
0.53
0.917
1.00
2.70
7.86
11.4
19.3
Volume and Density
Relationship Between Volume and Density for Identical Masses of Common Substances
Substance
Cube of substance
(face shown actual size)
Mass
(g)
Volume
(cm3)
Lithium
10
19
0.53
Water
10
10
1.0
Aluminum
10
3.7
2.7
Lead
10
0.58
11.4
Density
(g/cm3)
Consider Equal Masses
Equal masses…
…but unequal volumes.
aluminum
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 71
The object with the
larger volume
(aluminum cube) has
the SMALLER density.
gold
Consider Equal Volumes
Mass
Density =
Volume
Equal volumes…
…but unequal masses
The more massive object
(the gold cube) has the
GREATER
_________ density.
aluminum
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 71
gold
Specific Gravity
cork
0.25
0.9
aluminum
2.7
Jaffe, New World of Chemistry, 1955, page 66
ice
water 1.0
Cube
Representations
1 m3 = 1 000 000 cm3
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 119
8 cm3
Volume
VolumeVolume
==length
6 cm= xx362width
cm3x x3 height
cm
2 cm
2 cm
2 cm
3 x 2 xcm
V = 2length
cm
cm
width
height
V =x82xcm
4 cm
3 cm
1 cm
2 cm
6 cm
Volume =
Volume = 24 cm3
Dorin, Demmin, Gabel, Chemistry The Study of Matter 3rd Edition, page 41
-
Density Triangle
D = M
V
M
M = DxV
ass
D
ensity
V
olume
V = M
D
Which liquid has the highest density?
least dense
1 <
3
<
5
<
1
3
2
Coussement, DeSchepper, et al. , Brain Strains Power Puzzles 2002, page 16
5
4
2
<
4
most dense