Physical Chemistry , 1st ed.

Using the equation Fma, this force corresponds to a mass of

248 Nm9.81 

m

s^2



m25.3 kg

where we have used the fact that 1 N 1 kgm/s^2. At a density of 1.01 g/mL,

this is

25.3 kg ^1

1

00

k

0

g

g

1

1

.0

m

1

L

g

^1

1

c

m

m

L

3

2.50 104 cm^3

where we have used the equality 1 cm^3 1 mL in the last step. For an area

of 100.0 cm^2 , this corresponds to a column having a height of



2.5

1

0

0

0.0

10

cm

(^4) c
2
m^3
250. cm
That’s almost 8 feet high! Figure 7.29 gives you an idea how high this is.
7.8 Colligative Properties 199
Figure 7.29 The osmotic pressure of a 0.010-molal solution will support a 100-cm^2 column
of solution that is about the height of a baby giraffe!
© D. Robert Franz/CORBIS