Phase diagrams liquid benzene

Fig. 15. Isobaric vapor—liquid—liquid (VLLE) phase diagrams for the ethanol—water—benzene system at 101.3 kPa (D-D) representHquid—Hquid tie-lines (A—A), the vapor line I, homogeneous azeotropes , heterogeneous azeotropes Horsley s azeotropes, (a) Calculated, where A is the end poiat of the vapor line and the numbers correspond to boiling temperatures ia °C of 1, 70.50 2, 68.55 3, 67.46 4, 66.88 5, 66.59 6, 66.46 7, 66.47, and 8, the critical poiat, 66.48. (b) Experimental, where A is the critical poiat at 64.90°C and the numbers correspond to boiling temperatures ia °C of 1, 67 2, 65.5 3, 65.0 ...

Figure 123-1 The liquid-solid phase diagram for ethyl benzene-toluene mixtures.

Figure 1.12 shows a liquid-liquid-vapor phase diagram of isopropyl alcohol (l)-benzene (2)-water (3) mixture. Figure 1.12 shows the critical point of liquid-liquid equilibrium (cr) in which the compositions of two equilibrium liquid phases are identical. The thin line shows the vapor line for the region of two liquid phases Reg. On this line, there are points of compositions of vapor that... 

Figure 7.12 shows a liquid-vapor phase diagram for positive deviations from Raoult s law. Each component has a higher-than-expected vapor pressure, so the total pressure in equilibrium with the liquid solution is also higher than expected. Ethanol/benzene, ethanol/chloroform, and ethanol/water are systems that show a positive deviation from Raoult s law. Figure 7.13 shows a similar diagram, but for a solution that shows a negative deviation from Raoult s law. The acetone/chloroform system is one example that exhibits such nonideal behavior. 

Figure 6.11 shows a pressure-composition liquid-vapor phase diagram of ethanol and diethyl ether for a fixed temperature of 20 C. Compare Figure 6.11 with Figure 6.2, which represents the nearly ideal mixmre of benzene and toluene. Figure 6.12 shows the temperature-composition phase diagram of the same mixture for a fixed pressure of 1.84 atm. Compare this figure with Figure 6.3. This system exhibits positive deviation from Raoult s law. The vapor pressure is larger than it would be if the solution were ideal, and the solution boils at a lower temperature than if it were an ideal solution.

Solid + Liquid Equilibria in Less Ideal Mixtures We should not be surprised to find that the near-ideal (solid + liquid) phase equilibria behavior shown in Figures 8.20 and 8.21 for (benzene + 1,4-dimethylbenzene) is unusual. Most systems show considerably larger deviations. For example, Figure 8.22 shows the phase diagram for. vin-C Hw +. The solid line is the fit of the... 

The phase diagrams of an ammonium IL, [Be(Ci)2C N] [NO3], with benzene and toluene have shown low immiscibility in the liquid phase with UCST at high IL mole fraction [99]. 

FIGURE 11.18 A phase diagram of temperature versus composition (mole fraction) for a mixture of benzene and toluene. Liquid composition is given by the lower curve, and vapor composition is given by the top curve. The thin region between curves represents an equilibrium between phases. Liquid and vapor compositions at a given temperature are connected by a horizontal tie line, as explained in the text. 

It is unusual to find systems that follow the ideal solution prediction as well as does (benzene+ 1,4-dimethylbenzene). Significant deviations from ideal solution behavior are common. Solid-phase transitions, solid compound formation, and (liquid 4- liquid) equilibria often complicate the phase diagram. Solid solutions are also present in some systems, although limited solid phase solubility is not uncommon. Our intent is to look at more complicated examples. As we do so, we will see, once again, how useful the phase diagram is in summarizing a large amount of information. 

Figure 14.29 shows the (solid + liquid) phase diagram for (benzene + hexafluoro-benzene). A congruently melting solid molecular addition compound with the formula QFU-CeFe ) is evident in this system.26 The rounded top of the freezing curve (solid line) for the addition compound results from almost complete dissociation of the addition compound in the liquid mixture. In other words, benzene and hexafluorobenzene act as independent molecular species in the liquid state and combine together as the addition compound only in the solid state. 

Treybal, in his book Liquid Extraction [1], works equilibrium material balances with triangular coordinates. The most unique and simple way to show three-phase equilibrium is a triangular diagram (Fig. 7.1), which is used for extraction unit operation in cumene synthesis plants [2], In this process benzene liquid is used as the solvent to extract acetic acid (the solute) from the liquid water phase (the feed-raffinate). The curve D,S,P,F,M is the equilibrium curve. Note that every point inside the triangle has some amount of each of the three components. Points A,... 

A typical experimental phase diagram for the system toluene-benzene is sketched in Figure 34.4 from which it can be seen that this diagram corresponds exactly in form to a superposition of the liquid and vapour curves derived in Figures 34.2 and... 

Obtain (or plot from data) a phase diagram for the benzene/toluene system. Vapor-liquid equilibrium behavior of binary systems can be represented by a temperature-composition diagram at... 

Figure 2. The phase diagram water/benzene/pentafethylene glycol) dodecyl ether at 30°C. Key IM, inverse micellar solution LLC, lamellar liquid crystal and unmarked, aqueous micellar solution.

FIGURE 4.16 T-x-y phase diagram for benzene(l) -i- cyclohexane(2) mixtures at 1 atm calculated from UNIQUAC compared with data. (Kojima, K. Tochigi, K. Predictiou of Vapor-Liquid Equilibrium by the ASOG Method. New York Elsevier Scieutific Publishiug Co., 1979. With permissiou.)... 

Location of the Form 1/Form 2/liquid triple point in the phase diagram of benzene. The triple point is dednced from the extrapolated intersection of the Sj-S2 transition cnrve with that of the S-L fusion curve. (The data were plotted from published values from Refs. 13, 21.)... 

Fatty acids have a lower solubility in typical ionic detergent solutions than in bile acid solutions, for a given micellar concentration. To paraphrase, the micellar zone in the ternary phase diagram of this system (ionic detergent-fatty acid-water) is smaller than that in the system bile acid-fatty acid-water. Small has constructed the sodium oleate-oleic acid-water phase diagram (32) the micellar zone is extremely small because of the formation of liquid crystalline phases of oleic-sodium oleate at very low oleic acid/ sodium oleate ratios. In unpublished experiments carried out several years ago, we compared the solubility of lauric acid in 40 mM solutions of sodium taurodeoxycholate and sodium glycodeoxycholate with that in sodium octyl benzene sulfonate. Lauric acid at concentrations of 1, 5, and 10 mM was completely soluble in these bile acid solutions at pH 6.3. By contrast, a 5 mM concentration of lauric acid in sodium octyl benzene sulfonate solution was completely turbid. 

Comments The states of the pure liquid and vapor components are shown in Figure 11-2. Benzene at the bubble temperature corresponds to point L, (hypothetical liquid), and at the dew temperature to point V, (true vapor). Toluene at the bubble temperature is shown by point (true liquid), and at the bubble temperature by point (hypothetical vapor). For demonstration purposes these states are shown on the same P-H graph. In reality, each component must be plotted on its own phase diagram. 

Figure 2.5 Phase diagrams of C14C2 in alkanes (from octane to hexadecane) and two different aromatic oils phenyl octane and ethyl benzene (S = solid, U = Lamellar liquid crystal,...

Figure 9.12 Vapor-liquid phase equilibrium in a benzene-toluene solution as a function of pressure at 23°C. (a) The total vapor pressure as a function of the mole fraction of benzene in the liquid, (b) The total vapor pressure as a function of the mole fraction of benzene in the vapor, (c) The pressure-composition phase diagram constructed by combining plots (a) and (b). The line/-g is the tie line corresponding to the system at point c.

Another common way of representing a binary liquid-vapor equilibrium is through a temperature-composition phase diagram, in which the pressure is held fixed and phase coexistence is examined as a function of temperature and composition. Figure 9.13 shows the temperature-composition phase diagram for the benzene-toluene system at a pressure of 1 atm. In Figure 9.13, the lower curve (the boiling-point curve)... 

Figure 9.13 Temperature-composition phase diagram for the liquid-vapor equihbrium in benzene-toluene mixtures at 1 atm. The boihng points of toluene and benzene are 110.6°C and 80.1°C, respectively.

Figure 2.2(b) shows an example of the projection onto the T - x plane of the phase diagram of a two-component mixture of naphthalene and benzene. The line CQE(sa/1) is the boundary between the liquid mixture and the solid SA phase, while the line DE is the boundary between the liquid mixture and the solid SB phase. At temperature near 60°C, for instance, a crystalline solid SA of pure naphthalene (point P) is in equilibrium with the liquid mixture of the composition at point Q. The special point E at temperature Te where sa/1 and 1/sb cross is called the eutectic point. Below Te, the solid is separated into two pure crystals SA and SB. 

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