```VLab: Density: Answers
Use this to check your work. Remember that while the numerical answers may vary
slightly, it is the process used to get those answers that is important.
Data & Observations
Table 1: Data for Objects 1-4
Object Mass
Initial
Final Object
#
(g)
volume volume volume
(mL)
(mL)
(mL)
1
24.7
5.0
14.5
9.5
2
15.6
5.0
11.0
6.0
3
49.4
5.0
24.0
19.0
4
5.2
5.0
7.0
2.0
Object Mass Initial
Final Object Density
RESULTS
#
(g) volume volume volume (g/mL)
(S = sinks; F = floats)
(mL)
(mL)
(mL)
Water Ethanol Gasoline Seawater
5 12.8
5.0
19.0
14.0
0.9
F
S
S
F
6 47.3
5.0
7.5
2.5
18.9
S
S
S
S
7 180.8
5.0
21.0
16.0
11.3
S
S
S
S
8 36.5
5.0
18.5
13.5
2.7
S
S
S
S
9 136.5
5.0
22.5
17.5
7.8
S
S
S
S
10 26.7
5.0
8.0
3.0
8.9
S
S
S
S
11 15.6
5.0
24.5
19.5
0.8
F
S
S
F
Analysis & Conclusions
1.
2. slope = change in y/change in x
m = y/x
m = (39.0 - 26.0)g/(15.0 - 10.0)mL
m = 2.6 g/mL
Since mass is the y-variable and volume is the x-variable, the slope calculation
requires that mass be divided by volume. Thus, the slope of the line represents
the density of the glass. Also, the resulting unit for this calculation (g/mL) is
appropriate for density.
3. Since the graph of mass versus volume produces a straight line, the density of
each piece of glass must be the same. Any increase in mass is paired with the
same incremental increase in volume (a linear relationship exists between the
variables).
4. Because each piece of glass has the same chemical composition, the density of
the two pieces would be equivalent. Although the second piece has a greater
mass, it would also have a greater volume, and the ratio of mass to volume
would remain constant.
5. Density is an intensive property. The mass of a sample has no effect upon its
density.
6.
#5 ice
#6 gold
#8 aluminum
#9 iron
#10 copper
#11 wood
7.
The objects should separate
according to their densities.
Aluminum will sink to the bottom,
since it is denser than any of the
liquids. Ice will sink in the ethanol,
but float above the water. Wood
sinks in the gasoline, but floats
above the ethanol. The order of
densities is indicated below:
GASOLINE
wood
ETHANOL
ice
WATER
SEAWATER
aluminum
aluminum > seawater > water > ice
> ethanol > wood > gasoline
8. The calculated density of the crown is 12.6 g/mL (56.7 g/4.5 mL), which rounds
off to 13 g/mL. This value indicates that the crown CANNOT be made of pure
gold, which has a density of 19.3 g/mL. The crown could be made of lead
(density = 11.3 g/mL) and plated with a layer of gold. The resulting crown would
be expected to have a density between that of lead and gold, but much closer
to that of lead. A density value of 13 g/mL supports this hypothesis.
9. d
10. a
11. c
```