Solubility Ternary systems

A triangular diagram shows the range of explosive mixtures in the hydrogen peroxide-benzene-water ternary system, and also includes data for various oxygenated water-soluble organic compounds. 

Fig. 21 Three-dimensional representation of a ternary system of two enantiomers in a solvent, S. One of the faces of the prism (at left) corresponds to the binary diagram of D and L (here a conglomerate). Shaded area isothermal section representing the solubility diagram at temperature T0. (Reproduced with permission of the copyright owner, John Wiley and Sons, Inc., New York, from Ref. 141, p. 169.)...

In the present case there are no ternary invariant equilibria in the system, partly due to the complete solid solubility of the A-B system. In a ternary system composed from three binary eutectic sub-systems, three univariant lines would meet in a ternary eutectic equilibrium ... 

Chapter 18 - The determination region of solubility of methanol with gasoline of high aromatic content was investigated experimentally at temperature of 288.2 K. A type 1 liquid-liquid phase diagram was obtained for this ternary system. These results were correlated simultaneously by the UNIQUAC model. By application of this model and the experimental data the values of the interaction parameters between each pair of components in the system were determined. This revealed that the root mean square deviation (RMSD) between the observed and calculated mole percents was 3.57% for methylcyclohexane + methanol + ethylbenzene. The mutual solubility of methylcyclohexane and ethylbenzene was also demostrated by the addition of methanol at 288.2 K. 

The procedure of Beutier and Renon as well as the later on described method of Edwards, Maurer, Newman and Prausnitz ( 3) is an extension of an earlier work by Edwards, Newman and Prausnitz ( ). Beutier and Renon restrict their procedure to ternary systems NH3-CO2-H2O, NH3-H2S-H2O and NH3-S02 H20 but it may be expected that it is also useful for the complete multisolute system built up with these substances. The concentration range should be limited to mole fractions of water xw 0.7 a temperature range from 0 to 100 °C is recommended. Equilibrium constants for chemical reactions 1 to 9 are taken from literature (cf. Appendix II). Henry s constants are assumed to be independent of pressure numerical values were determined from solubility data of pure gaseous electrolytes in water (cf. Appendix II). The vapor phase is considered to behave like an ideal gas. The fugacity of pure water is replaced by the vapor pressure. For any molecular or ionic species i, except for water, the activity is expressed on the scale of molality m ... 

Many different types of phase behaviour are encountered in ternary systems that consist of water and two solid solutes. For example, the system KNO3—NaNC>3— H20 which does not form hydrates or combine chemically at 323 K is shown in Figure 15.6, which is taken from Mullin 3 . Point A represents the solubility of KNO3 in water at 323 K (46.2 kg/100 kg solution), C the solubility of NaN(>3 (53.2 kg/100 kg solution), AB is the composition of saturated ternary solutions in equilibrium with solid KNO3 and BC... 

Boddu, V.M., Krishnaiah, A., and Viswanath, D.S. Liquid-liquid equilibria of the benzene + water + acetic acid ternary system and solubility of benzene in water effect of calcium chloride. J. Chem. Eng. Data, 46(5) 1172-1175, 2001. 

Maeda, K., Kuramochi, H., Shinkawa, T.,andFukui, K. Solubility oftwo salts containing sulfate and chloride ions in water for ternary systems at 313 K, 7 Chem. Eng. Data, 47(6) 1472-1475. 2002. 

SOLUBILITIES IN TERNARY SYSTEMS 2.8.1 Ternary Phase Diagrams... 

General solvent extraction practice involves only systems that are unsaturated relative to the solute(s). In such a ternary system, there would be two almost immiscible liquid phases (one that is generally aqueous) and a solute at a relatively low concentration that is distributed between them. The single degree of freedom available in such instances (at a given temperature) can be construed as the free choice of the concentration of the solute in one of the phases, provided it is below the saturation value (i.e., its solubility in that phase). Its concentration in the other phase is fixed by the equilibrium condition. The question arises of whether or not its distribution between the two liquid phases can be predicted. 

The amount of a solute that can be introduced into a solvent depends on its solubility, be it a gas (section 2.7.1), a solid nonelectrolyte (section 2.7.2), or an electrolyte (section 2.7.3). Ternary systems, which are the basic form of solvent extraction systems (a solute and two immiscible solvents), have then-own characteristic solubility relationships (section 2.8.1). 

Binary data can be represented with a T—x diagram that shows the mutual solubility as function of temperature. Most of the binary systems belong to one of the classes in Fig. 10.1. For ternary systems, experimental data are usually obtained at constant temperature and given in ternary diagrams. There are many types of systems, but more than 95% belong to one of the two classes shown in Fig. 10.1. 

Fig. 10.1 Different types of liquid-liquid systems, (a), (b) Solubility as function of temperature for binary systems (c), (d) ternary systems. (Dashed lines are examples of tie lines, which connect the two phases in equilibrium located at the binodal.)...

The behaviour of ternary systems consisting of two polymers and a solvent depends largely on the nature of interactions between components (1-4). Two types of limiting behaviour can be observed. The first one occurs in non-polar systems, where polymer-polymer interactions are very low. In such systems a liquid-liquid phase separation is usually observed each liquid phase contains almost the total quantity of one polymer species. The second type of behaviour often occurs in aqueous polymer solutions. The polar or ionic water-soluble polymers can interact to form macromolecular aggregates, occasionally insoluble, called "polymer complexes". Examples are polyanion-polycation couples stabilized through electrostatic interactions, or polyacid-polybase couples stabilized through hydrogen bonds. 

J The concept of counter-phases. When a stable compound penetrates from a binary into a ternary system, it may extend right across the system or exhibit only limited solubility for the third element. In the latter case, any characterisation also requires thermodynamic parameters to be available for the equivalent metastable compound in one of the other binaries. These are known as counter-phases. Figure 6.16 shows an isothermal section across the Fe-Mo-B system (Pan 1992) which involves such extensions for the binary borides. In the absence of any other guide-... 

In addition to the experimental results of phase equilibria, the correlation with the widely known GE models was assigned to. It was indicated by many authors that SLE, LLE, and VLE data of ILs can be correlated by Wilson, NRTL, or UNIQUAC models [52,54,64,79,91-101,106,112,131,134]. For the LLE experimental data, the NRTL model is very convenient, especially for the SLE/LLE correlation with the same binary parameters of nonrandom two-liquid equation for mixtures of two components. For the binary systems with alcohols the UNIQUAC equation is more adequate [131]. For simplicity, the IL is treated as a single neutral component in these calculations. The results may be used for prediction in ternary systems or for interpolation purposes. In many systems it is difficult to obtain experimentally the equilibrium curve at very low solubilities of the IL in the solvent. Because this solubility is on the level of mole fraction 10 or 10 , sometimes only... 

Phase Behavior. One of the pioneering works detailing the phase behavior of ternary systems of carbon dioxide was presented in the eady 1950s (12) and consists of a compendium of the solubilities of over 260 compounds in liquid (21—26°C) carbon dioxide. This work contains 268 phase diagrams for ternary systems. Although the data reported are for liquid C02 at its vapor pressure, they yield a first approximation to solubilities that may be encountered in the supercritical region. Various additional sources of data are also available (1,4,7,13). 

According to K. von Hauer,36 a soln. of potassium bromide sat. at 15° deposits almost all its bromide when repeatedly heated and cooled with an excess of potassium iodide and potassium iodide dissolves in a sat. soln. of potassium chloride almost as copiously as in water. A. Etard has measured the mutual solubility of potassium bromide and chloride, potassium chloride and iodide, and potassium bromide and iodide, and found that the sum of the salts dissolved can usually be represented as a straight line when plotted with temp., and the vanishing point where the water has disappeared, coincides with the m.p. of the constituent with the lower m.p. The solubility of the ternary system potassium chloride, bromide, and iodide, could not be determined as a function of temp, because the three salts cannot exist simultaneously in a sat. soln.—the chloride remains undissolved in the presence of the other two salts. G. J. Mulder (1864) found that the solubility of potassium iodide is diminished in the presence of potassium sulphate. J. N. Bronsted measured the solubility of potassium iodide in soln. of potassium hydroxide of different cone. 

The isothermal solubility curve of mixtures of potassium sulphate and sulphuric acid expresses the composition of the soln. at 25° in equilibrium with the solid phase or phases, when the mol. ratio of K2SO4 and SO3 per 1000 grms. of soln. are plotted as co-ordinates. The ranges of stability in the ternary system K20—S03—H20, are diagrammed in Fig. 51, where the conditions have been studied in the vicinity of the SOs-apex, as far as the formation of KHS207, hut not as far as the well-known potassium pyrosulphate. The meaning of the diagram... 

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