Vapour/liquid equilibria

To understand the conditions which control sublimation, it is necessary to study the solid - liquid - vapour equilibria. In Fig. 1,19, 1 (compare Fig. 1,10, 1) the curve T IF is the vapour pressure curve of the liquid (i.e., it represents the conditions of equilibrium, temperature and pressure, for a system of liquid and vapour), and TS is the vapour pressure curve of the solid (i.e., the conditions under which the vapour and solid are in equili-hrium). The two curves intersect at T at this point, known as the triple point, solid, liquid and vapour coexist. The curve TV represents the... 

Brown, I. (1952) Liquid-vapour equilibria. III. The systems benzene-heptane, hexane-chlorobenzene, and cyclohexane-nitrobenzene. Austral. J. Sci. Res. 5A, 530-540. 

Equation (3) is applicable to various equilibria such as solid-liquid equilibria, liquid-vapour equilibria and equilibria between two solid modifications. The Clapeyron s equation for these various equilibria can be easily obtained as follows ... 

Applications of Clapeyron-Clauslus Equation for Liquid = Vapour Equilibria... 

Liquid-vapour equilibria for Cl -COCl have been calculated on the assumption that the system conforms to ideality [541]. In the region of low dichlorine concentration (<2.5%), the system has been shown, by analysis of the gas and liquid phases, to behave consistently with these calculations. The temperature-composition diagrams are illustrated in Fig. 6.13 at 101.3 and 152.0 kPa [541]. 

Liquid-vapour equilibria in the phosgene-hydrogen chloride system have also been studied in connection with the problems associated with the separation of these two materials during the production of isocyanates. The system has been examined under atmospheric pressure within the range of the boiling points of the materials, ca. 8 to -85 C. The temperature-composition curve is illustrated in Fig. 6.14 [789] it shows large deviations from ideality. 

II- Modelling liquid-vapour equilibria in the H2O-H2S, H2O-CH4 and H2O-CO2 systems, Chem. Geol. 251, 50-57 (2008). 

After the optimum additive has been chosen the liquid-vapour equilibria of the ternary or multicomponent systems have to be determined as exactlj- as possible in extractive as well as in azeotropic distillation. For this reason Null and Palmer [76] looked for methods allowing equilibrium values to be obtained from as few experimental data as possible. 

Liquid-vapour equilibria in the systems formed by arsenic trichloride and its most probable impurities, i.e. SOaCl, SOCI2, PSCI3, and POCI3, have been studied, showing that the latter two are the most difficult to remove by simple distillation. Substituted halogenoarsines react in the presence of triethylamine with aldoximes to give the esters R As(ON CHR >2 and... 

Even though the graphical correlation works well and is simple to use for binary systems, attempts have continued to find suitable functional forms to describe the properties of homologous mixtures in terms of composition and chain length. McGlashan and co-workers used the zeroth approximation of the lattice theory for molecules of different sizes to account for their measurements of liquid vapour equilibria and enthalpies of mixing of n-alkanes. The relations used were ... 

Sanchez IC, Lacombe RH (1974) Theory of liquid-liquid and liquid-vapour equilibria. Nature 252 381-383... 

Brown, I. Ewald, A. H. Liquid-vapour equilibria. 1. The system carbon tetrachloride - cyclohexane and water - acetic add Aust. 

Lepori, L. Matteoli, E. Marongiu, B. Isothermal liquid-vapour equilibria of mixtures containing organic compounds. 3. Excess Gibbs free energies of cyclohexane -I- a linear ether Fluid Phase Equilib. 1988,42, 229-240... 

Brown, I. Smith, F. Liquid-vapour equilibria. IX. The systems n-propanol + benzene and n-butanol + benzene at 45.deg.C Aust. J. Chem. 1959,12, 407-412... 

Zawisza, A. C. Glowka, S. Liquid-vapour equilibria of acrylonitrile - n-pentane and acetonitrile - n-pentane systems at 60,90 and 120.deg.C Bull Acad. Pol. ScL, Ser. Sci. Chim. 1969,17,373-379... 

Isothermal phase-change calorimeters based on liquid + vapour equilibria have been used for the determination of energies of polymerization. The monomer was sealed into an ampoule immersed in the calorimetric liquid e.g. carbon tetrachloride, benzene, toluene) contained in a tube, which was suspended from a balance and surrounded by vapour of the same refluxing liquid. As the polymerization proceeded the heat liberated by the reaction caused liquid to vaporize from the tube and was measured by the consequent loss in mass. ... 

Dynamic is a key word in our understanding of what is happening in liquid-vapour equilibria. It implies continuous activity and helps explain many everyday phenomena relating to the behaviour of liquids, including the variation of boiling point with atmospheric pressure. 

On the basis of assumptions similar to those made in liquid-vapour equilibria, an expression similar to Eq.(4.6) may also be obtained for solid-vapour equilibria. 

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