Multicomponent Equilibrium Thermodynamics - Elements of Environmental Engineering: Thermodynamics and Kinetics - page 65

r

FIGURE 3.5 The meniscus for water confined in a capillary.

isanimportantprocessinsoilmatrices.Itisimportantinunderstandingtheinfiltration
of nonaqueous phase liquids in to sub-surface soil. The phenomenon is also important
in understanding the nucleation of bubbles in a liquid. To support a vapor bubble of
radius r in water, the pressure must exceed that of the hydrostatic pressure by 2 σ /r .

For a 100 nm radius bubble in water at room temperature, this gives a pressure of
14.6 atm. To nucleate a bubble of zero radius (i.e., to start boiling) therefore, we need
infinite pressure. This is one of the reasons for the significant super-heating required
for boiling liquids.

12000

10000

CCl 4
Cl 2 CH-CH 3
Cl 3 C-CH 3

8000

6000

4000

2000

0

0.00320 0.00325 0.00330 0.00335 0.00340 0.00345

(1/T)/K -1

FIGURE 3.6 Variation of activity coefficients at infinite dilution in water for typical environ-
mentally significant compounds versus temperature. (From Tse, G., Orbey, H., and Sandler,
S.I. 1992. Environmental Science and Technology 26, 2017-2022.)