CHAP. 7: PHASE EQUILIBRIA [CONTENTS] 211
T s(^0) x 1 (l^1 ) x(l 12 ) 1
(l 1 ) + (l 2 )
K
Obr.7.9:Isobaric diagram of a two-component system with two liquid phases. The curve describes
the dependence of equilibrium temperature on the composition of the partially miscible liquid phases
1 and 2. Point C is the upper critical point of solution.
7.8 Liquid-liquid equilibrium
Some liquids are only partially mutually miscible (e.g. water and phenol), and their mixture
can split into two liquid phases. The dependence between the composition of the coexisting
liquid phases and temperature is studied in this connection. The pressure dependence is small
and usually it is not studied.
Note:Equilibrium between liquid phases is typical for mixtures; it does not exist in one-
component systems.