Boiling point curve

Fig. 5. Boiling point curve for the HF—water system, where A represents an a2eotrope at 37.73 wt % HF, L is the Hquid, and V the vapor (25,26).

Fig. 8. Boiling and freezing temperatures of KOH solutions (33). The boiling point curve assumes a pressure of 101.3 kPa (760 mm Hg).

Example 8-5 Boiling Point Curve and Equilibriiun Diagram for Benzene-Toluene Mixture... 

Kojima, K., Tochigi, K., Seki, H. and Watase, K. (1968) Kagaku Kogaku 32, 149. Determination of vapour-liquid equilibrium from boiling point curve. 

Composition change causes shift in boiling point curve. 

Supercritical fluids represent a different type of alternative solvent to the others discussed in this book since they are not in the liquid state. A SCF is defined as a substance above its critical temperature (Tc) and pressure (Pc)1, but below the pressure required for condensation to a solid, see Figure 6.1 [1], The last requirement is often omitted since the pressure needed for condensation to occur is usually unpractically high. The critical point represents the highest temperature and pressure at which the substance can exist as a vapour and liquid in equilibrium. Hence, in a closed system, as the boiling point curve is ascended, increasing both temperature and pressure, the liquid becomes less dense due to thermal expansion and the gas becomes denser as the pressure rises. The densities of both phases thus converge until they become identical at the critical point. At this point, the two phases become indistinguishable and a SCF is obtained. 

Thus, the addition of two phases A and B is shown on the diagram by point C on the straight line joining the two phases, whilst the difference (A — B) is found by a point C on the extension of the line AB. If, as shown in Figure 11.24, a phase represented by C in the region between the dew-point and boiling-point curves is considered, then this phase will divide into two phases A and B at the ends of a tie line through the point C, so that ... 

Show that the experimental data for the boiling point curve for this solution is compatible with Equation (14.82). 

Figure 3. True Boiling Point Curves of Polymers...

Fio. 23.—Boiling Point Curves of Mixtures of Chlorine and Bromine. 

In this case, the boiling-point curve passes through a maximum (again, at the same composition where P-xB passes through a minimum) where xBq = xBdp. This maximum-boiling... 

In earlier years, API set up calculation procedures to convert these more easily run ASTM D86 and D1160 boiling point curves to the sought TBP curve data. This book presents a unique program, named ASTM4, which receives ASTM curve inputs, both D86 and D1160 data, and converts them to TBP data. API 3A1.1 and API 3A2.1 methods are... 

Table IV shows the properties of a typical C3 motor polymer of fullboiling range. It is somewhat heavier than the C3-C4 polymer and the octane rating is possibly a one-half number lower on the C3 polymer. The required equipment is the same as shown in Fig. 1. When C3 motor polymer is made, however, the debutanizer and rerun columns are not required. Figure 6 shows a true-boiling-point curve of typical C3 motor polymer.

As the boiling point curves of the three types of solutions are different, the behaviour of these solutions on distillation will be different. 

The olefin feed stocks were all commercial grade of >95% purity, used without further purification. Light products mass spectrometry. Liquid analysis was done by gas chromatography and boiling point curves by ASTM method d-2887 (gas chromatography). 

In many cases the deviations are large enough to result in maxima or minima in the vapor-pressure and boihng-point curves, as shown in Fig. 2. Systems for which the boiling-point curves have a maximum include acetone-chloroform and hydrogen chloride-water systems with a minimum include methanol-chloroform, water-ethanol, and benzene-ethanol. At a maximum or a minimum, the compositions of the liquid and of the vapor are the same accordingly, there is a point of tangency of the curves L and Kand of the curves L and... 

Liquid-vapor phase diagrams, and boiling-point diagrams in particular, are of importance in connection with distillation, which usually has as its object the partial or complete separation of a liquid solution into its components. Distillation consists basically of boiUng the solution and condensing the vapor into a separate receiver. A simple one-plate distillation of a binary system having no maximum or minimum in its boiling-point curve can be understood by reference to Fig. 3. Let the mole fraction of B in the initial solution be represented by... 

Figure 3. Simulated distillation boiling point curves for virgin bitumen, mal-tenes, and asphaltenes...

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