Calculating Density Homework Answers
Page 1
1) 7.8 g/cm3
2) Benzene is denser. Benzene’s density is .80 g/cm3 and Ethonal is .78 g/cm3
3) Gold will have a greater mass since more molecules will fit into a volume of 5.0 cm 3
4) 8.96 g/cm3
5) 0.00196 g/mL
Page 2 (remember to round to the nearest 10th)
1) D=m/v
D= 50g/6.4 cm3
D=7.8 g/cm3
2) V=m/D
V= 20g/(8g/cm3)
D=2.5 cm3
3) D=m/v
D= 35g/10mL
4) V=m/D
D=3.5 g/mL
3
V= 55g/(3.0g/cm )
D=18.3 cm3
Page 3: Diagram #1
1) The Aluminum sample and the Lead sample have the same mass, since the balance is not tipped toward
either one.
2) The Aluminum sample has more volume than the lead sample because it takes up more space.
3) Lead is more dense than aluminum.
4) The Lead must me more dense since it’s mass is equal to a much larger sample evident that that amount
of mass can fit in a smaller amount of space.
Diagram #2
5) In this diagram the Lead sample has more mass than the aluminum sample, since the balance is tipped
toward that side.
6) The volume of the samples is the same.
7) Lead is more dense than the aluminum.
8) Even though the lead and aluminum have the same volume, the lead has a higher density and therefore
more molecules can fit in the same amount of space.
Page 4
1) Density of Gypsum: 2g/cm3
Density of Shale: 3g/cm3
2) Both the gypsum and the shale will sink in water because they are both more dense than liquid water
(1g/cm3)
3) Both the density of the water sample and the density of the lake are still 1g/cm3. The only way to change
density is to change temperature or pressure.
4) M= VxD
M= 6cm3 x 2.7g/cm3
M = 16.2g
Page 5
1) As a substance is heated it’s density will decrease (b)
2) As pressure is increased on a substance, density will also increase. (a)
3) a) less than 2.7g/cm3
4) d. The density remains the same
5) Warm air rises while cold air sinks.
Warm air is less dense than cold air and fluids layer based on density, therefore colder denser air will sink
beneath warmer less dense air.
Page 6
1&2
4) Material A: Density of A, B & C: 1.75 g/cm3
5)Material B: Density of A, B & C: 0.4 g/cm3
6)Material A: 1.75 g/cm3
7)Material B: 0.4 g/cm3
8) If a material is less dense than water it will have a more gentle slope than water and the plot will be
beneath the plot of water. The density will calculate to less than 1.0g/cm 3
If a material is more dense than water it will have a steeper slope that water and the plot will be above the
plot of water. The density will calculate to more than 1.0g/cm3
The greater the density, the steeper the slope.
Page 7
A
1) A
2) C
B
3) B
4) B
5) A
C