Phase diagrams water-sodium chloride

Figure 4 Phase diagram of sodium chloride/water.

Using one of the pure alkyl aryl sulfonates with water, sodium chloride and decane, we are investigating simultaneously the phase behavior, the structure of the phases, and the interfacial tensions between them. Ultralow tensions are observed in this system (10), and it is important to know why they occur, when they do (13). Our first aim is to establish the equilibrium phase diagram of surfactant-water-decane as a function of... 

Many binary systems, both ideal and nonideal, have phase diagrams of the simple eutectic type. The phase diagram, water-salt, is the simple eutectic type if the salt does not form a stable hydrate. The diagram for H20-NaCl is shown in Fig. 15.10. The curve ae is the freezing-point curve for water, while efis the solubility curve, or the freezing-point curve, for sodium chloride. 

Figure 39. Phase diagram of sodium laurate (dodecanoate)/sodium chloride/water (reproduced from [167]). (A) Salt+various curds,...

Sodium Chloride Solubilities in Amine-Water Mixtures. To determine to what extent the amines reduce the sodium chloride solubility and to be able to calculate the maximum obtainable magma densities during crystallization, sodium chloride solubilities in the amine-water mixtures were measured. The sodium chloride solubilities were determined at the crystallization conditions in the single liquid phase area. The solubility diagram of sodium chloride in DMiPA-H20 at T = 5 °C is displayed in Figure 6. At amine fractions above 0.8 the sodium chloride solubility approaches zero for both DiPA and DMiPA. 

Sodium chloride-water system, phase diagram of, 22 801—802 Sodium chlorite, 6 133 Sodium chloroacetate, 1 139—140 Sodium AT-chlorobenzenesulfonamide (chloramine B), 4 54 Sodium AT-chloroimidodisulfonate, 4 54... 

It is also good practice to have each salt s phase-diagram, in order to know how they would precipitate under supercritical conditions. For example, sodium chloride yields crystals that are larger than sodium sulphate [28], which facilitates its separation by filtration or using cyclones. When a sodium chloride solution is heated, it reaches an L/V equilibrium zone, where water-evaporation takes place, and the salt s concentration in the liquid drops, thus producing formation of larger crystals (10 tolOO (am). In contrast, sodium sulphate reaches... 

Figure 16.2. Some phase diagrams, (a) The water end of the system potassium chloride and water, (b) The water end of the system sodium chloride and water, (c) The water end of the system magnesium sulfate and water the heptahydrate goes to the mono at 150°C, and to anhydrous at 200°C. (d) /3-methylnaphthalene and /S-chloronaphthalene form solid solutions, (e) Mixtures of formamide and pyridine form a simple eutectic, (f) These mixtures form binary eutectics at the indicated temperatures and a ternary eutectic at mol fractions 0.392 dibenzyl, 0.338 diphenyl, and 0.27 naphthalene.

Figure 21.38. Phase diagram of the sodium palmitate (NaP)/sodium chloride/water system at 90°C (reproduced from ref. (195) with permission of Academic Press)...

FIGURE 7.15. Sodium chloride-water phase diagram. 

Hamano, A., Hamado, K. and Kumamoto, K., Phase diagram of the sodium hypochlorite-sodium chloride-water system, Nippon Kagaku Kaishi, 7,1066, 1977. 

Microemulsions are ternary systems containing oil, water, and surfactant. The terms oil and water in a microemulsion system normally refer to oil phase (oil and oil soluble components such as cyclosporine) and aqueous phase (water and water soluble components such as sodium chloride), respectively. The phase behavior of water-oil-surfactant mixtures was extensively studied by Winsor (1948). Based on his experimental observations, Winsor classified equilibrium mixtures of water-oil-surfactant into four systems (1) type I (Winsor I) system where water continuous or oil-in-water (0/W) type microemulsion coexists with the oil phase. In these systems, the aqueous phase is surfactant-rich (2) type II (Winsor II) system where oil continuous or water-in-oil (W/0) type microemulsion coexists with the aqueous phase. In these systems, the oil phase is surfactant-rich (3) type III (Winsor III) system where bicontinuous type microemulsion (also referred to as surfactant-rich middle-phase) coexists with excess oil at the top and excess water at the bottom and (4) type IV (Winsor IV) system where only a single-phase (microemulsion) exists. The surfactant concentration in type IV microemulsion is generally greater than 30 wt%. Type IV microemulsion could be water continuous, bicontinuous, or oil continuous depending on the chemical composition. The phase behavior of microemulsions is often described as a fish diagram shown in Figure lO.I (Komesvarakul et al. 2006). 

FIGURE 14.9 Phase diagram of the system (a) water-SDS + butanol-methylene chloride. The aqueous phase in (b) contains sodium molybdate in different concentrations. With increasing salt content from 0.2 up to 0.8 M, the single phase region becomes smaller. (Reprinted from Aubry, J.M. and Bouttemy, S., J. Am. Chem. Soc., 119, 5286, 1997. With permission.)... 

This applies to the sodium chloride-water system which is an exemplary case. Fig. 2 gives a schematic p-T-diagram of a two component system with very different critical temperatures. One observes a critical curve which is a projection from the three-dimensional pressure-temperature-composition diagram on the p-T-plane. The curve extends uninterrupted between the critical points of the two pure components. The projection of a three-phase-surface, S2LG, between a quadruple point and the triple point T2 can also be seen. It does not intersect the critical curve in this example. In the right part of Fig. 2 we have a P-x-section taken between M and B in the previous diagram. At CP the critical curve penetrates the P-x-plane. 

The relationship between solubility and phase behavior may be illustrated using the diagram of the binary sodium chloride-water system (Fig. 2). To read this diagram, remember that at any particular point, the magnitude of the x coordinate equals gross composition (expressed as percent sodium chloride), whereas that of the y coordinate equals temperature. The phase boundaries within the diagram, which in this case have been firmly established [25], define and separate regions within which qualitatively similar phase behavior is found. To describe phase behavior, one states the number of phases present. 

Figure 2 The phase diagram of the sodium chloride-water system. The dashed arrow depicts the variation of gross composition (starting from the water phase) as sodium chloride is added to an approximately equal quantity of water at 25 C. The solid arrow points to the coordinates of the solubility boundary (26.43%, 25°C) mentioned in the text. (From Ref. 25.)...

Same as Problem 8.25, except that the system of interest is sodium chloride-water. For the purpose of this problem assume that the vapor pressure of pure sodium chloride is zero at temperatures near room temperature and that the NaCl is 100% ionized. Omit any solid phases. Assume that both y, = 1.00. Draw the P-Xa diagram for 212 F and the T-Xa diagram for 14.7 psia. (Sodium chloride melts at 801°C and boils at 1413°C.)... 

FIGURE 11.14 Phase diagram for water and sodium chloride. If the diagram extended up above 100°C, it would also show the VLE. Observe the contraction of the scale between 30 and 60 wt% NaCl. (From Bertram, B. M. Sodium compounds (sodium halides). In Kirk-Othmer Encyclopedia of Chemical Technology, ed. 4, Vol. 22, Kroschwitz, J. I., and M. Howe-Grant, eds. Copyright 1997, New York Wiley, p. 360. Reproduced by permission of John Wiley and Sons, Inc.)... 

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