Liquids phase diagrams

Fig. 3. Vapor—liquid-phase diagram for the HCl—H2 O system (5) where (-) represents the demarcation between the two-phase region and the gas...

Fig. 5. Vapoi—liquid phase diagram of the H2O—P20 system at 101 kPa (1 atm), where 3 is ortho, 2 pyro, and 1 meta phosphoric acid. The soHd line...

The liquid line and vapor line together constitute a binary (vapor + liquid) phase diagram, in which the equilibrium (vapor) pressure is expressed as a function of mole fraction at constant temperature. At pressures less than the vapor (lower) curve, the mixture is all vapor. Two degrees of freedom are present in that region so that p and y2 can be varied independently. At pressures above the liquid (upper) curve, the mixture is all liquid. Again, two degrees of freedom are present so that p and. v can be varied independently/... 

Figure 8.14 Relationship between the (p. v) and (/. x) (vapor + liquid) phase diagrams for an ideal solution.

Figure 8.21 gives the ideal solution prediction equation (8.36) of the effect of pressure on the (solid + liquid) phase diagram for. yiC6H6 + xj 1,4-C6H4(CH3)2. The curves for p — OA MPa are the same as those shown in Figure 8.20. As... 

Figure 8.22 (Solid + liquid) phase diagram for. vin-CiaHut +. viCsHs. The circles are the experimental melting temperatures and the lines are the fit of the experimental results to equation (8.31). The dashed lines are the ideal solution predictions from equation (8.30).

Figure 8.23 (Solid + liquid) phase diagram for (. 1CCI4 +. yiCHjCN), an example of a system with large positive deviations from ideal solution behavior. The solid line represents the experimental results and the dashed line is the ideal solution prediction. Solid-phase transitions (represented by horizontal lines) are present in both CCI4 and CH3CN. The CH3CN transition occurs at a temperature lower than the eutectic temperature. It is shown as a dashed line that intersects the ideal CH3CN (solid + liquid) equilibrium line.

E8.8 (a) Construct the binary (vapor + liquid) phase diagram for an ideal... 

P8.4 The (solid + liquid) phase diagram for (.Yin-C6Hi4 + y2c-C6Hi2) has a eutectic at T = 170.59 K and y2 = 0.3317. A solid phase transition occurs in c-CftH at T— 186.12 K, resulting in a second invariant point in the phase diagram at this temperature and. y2 — 0.6115, where liquid and the two solid forms of c-C6H12 are in equilibrium. A fit of the experimental... 

The hydrophobic interaction results in the existence of a lower critical solution temperature and in the striking result that raising the temperature reduces the solubility, as can be seen in liquid-liquid phase diagrams (see Figure 5.2a). In general, the solution behaviour of water-soluble polymers... 

Figure 5.2 Liquid-liquid phase diagrams for a) aqueous solutions ofpoly(methacrylic acid) and ib) aqueous solutions of poly (ethylene glycols)...

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. 

An experimental investigation of equilibrium behavior of the systems composed of methylcyclohexane + ethylbenzene + methanol was carried out at 288.2 K. The liquid-liquid phase diagrams exhibit type 1 systems and indicate that methanol is totally miscible with the gasoline in a wide interval. Therefore, methanol may be considered as a good candied in gasoline formulations for vehicular fuels. 

Figure 7.13 Continuous changes of solid-liquid phase-diagram type from (a) ideal to (f) eutectic, showing (b) positive nonideality that progressively results in (c) a low-melting minimum, (d) a region of solid-solid immiscibility, or (e) complete closing of the solubility gap, culminating in (f) complete eutectic immiscibility.

Analysis of the growth process by LPE usually stipulates an equilibrium boundary condition at the solid-liquid interface. The solid-liquid phase diagrams of interest to LPE are those for the pure semiconductor and the semiconductor-impurity systems. Most solid alloys exhibit complete mis-... 

Phase equilibrium resulting in a UCST is the most common type of binary (liquid + liquid) equilibrium, but other types are also observed. For example, Figure 14.5 shows the (liquid + liquid) phase diagram for (xiH20 + jc2(C3H7)2NH. 7 A lower critical solution temperature (LCST) occurs in this system/ That is, at temperatures below the LCST, the liquids are totally miscible, but with heating, the mixture separates into two phases. 

Figure 14.19 (Solid + liquid) and (liquid + liquid) phase diagram for (xic-C6H 12 + X2CH3OH) at (a) p = 0.1 MPa and (b) as a function of pressure. In (a), the freezing curve extending to the eutectic is estimated and is represented by a dashed line to reflect this uncertainty. In (b), the freezing line at p = 229 MPa is estimated and is represented by a dashed line. The dash-dot line in (b) is the envelope enclosing the region with two liquid phases.

Figure 14.23 gives the (solid + liquid) phase diagram for (tetrachloromethane + 1,4-dimethylbenzene).19 The maximum in the (solid + liquid) equilibrium curve at X2 = 0.5 results from the formation of a solid addition compound with the formula CCl4-l,4-C6H4(CH3)2 that melts at the temperature corresponding... 

Figure 14.24 (Solid + liquid) phase diagram for X1CHCI3 + (CHjOCI. The dashed lines represent the melting temperatures and the eutectics for a metastable form of (CH3OCH2)2-2CHCl3(s).

Figure 14.26 (Solid + liquid) phase diagram for (xjAg + Cu) at p — 0.1 MPa. Reprinted with permission from M. Hanson and K. Anderko, Constitution of Binary Alloys, 2nd ed., McGraw-Hill, New York, 1958, p. 18.

Figure 14.27 (Solid + liquid) phase diagram for (xi Ag + j Au) at p = 0.1 MPa, an example of a system with complete miscibility in both the liquid and solid states.

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. 

Figure 14.29 (Solid + liquid) phase diagram for (xi C6H6 + X2C6F6). The dashed line represents expected melting points of the QHa-QF solid addition compound if the addition compound did not dissociate in the liquid mixture, while the dash-dot line represents partial dissociation in the liquid mixture.

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