Solution curves pressure

All experiments in this study were carried out under conditions where C02 and styrene are miscible. The solubilities of C02 and ethylbenzene (a model for styrene) in HDPE were determined at 80 °C and 243 bar. The HDPE samples were immersed in either pure C02 or a 36 wt % ethylbenzene/C02 solution within pressure vessels under these conditions for various times. Figure 10.1 shows results of a typical desorption experiment to determine the mass uptake of ethylbenzene for a given soak time the equilibrium mass uptake was found to be 4% and this was reached after approximately 5 h. Figure 10.2 illustrates the mass uptakes as a function of soak time the diffusivity of ethylbenzene in C02-swollen HDPE under these conditions was calculated by curve fitting to be 9.23 x 10 7 cm2/s. Attempts to determine the equilibrium mass uptake of neat ethylbenzene in HDPE at 80 °C failed because ethylbenzene dissolves polyethylene under these conditions. 

Fig. 10.13. Effect of dodecanol on the kinetic curves of expansion ratio change (a) and on the foam capillary pressure (b) foaming system curve 1 - 0.2% Volgonate solution curve 2 - 0.2% Volgonate + 0.1% dodecanol.

Figure 2. Experimental pair-distribution functions g(r) for 2 mol dm aqueous solutions of sodium chloride at room temperature and at 1 bar (lower curve) and 1000 bar (upper curve) pressures.

For a binary solution at constant composition, an expression of the form (9.1) is found for the slope of the vapor pressure curve as a function of temperature in which the latent heat of vaporization is the value for the solution. Solution vapor pressure curves can be represented as a set of parametric curves at constant composition on the vapor pressure diagram. 

Figure 3.1 Dependence of solvent vapor pressure over a solution on mole fraction of components in solution. Curve 1 ideal solution, pi/pi = X. Curve 2 negative deviation from ideality, Pi/pj < Xi- Curve 3 positive deviation from ideality, pi/p° > Xi.

The scale-up of a fixed-bed separation may be carried out by increasing the diameter of a column, the length of the packed bed, and/or the flow rate of the feed solution. The pressure drop through the column limits the length of the packed bed. The amount of adsorbate treated per unit time and the unit sectional area of a column will increase with the linear velocity of the feed. However, the slope of the breakthrough curve becomes gentle with an increase in the velocity, when the intraparticle resistance of solute transfer is dominant, and thus the fraction of the column capacity available at the break point will decrease. Therefore, the linear... 

Figure 5 bottom shows the measured pressure drop associated with the solution (curve a) and the solvent (curve b). A small but distinct increase in pressure drop is associated with the coil-stretch transition. To separate the polymer contribution, curve c shows curve a minus curve b now the polymer contribution can be seen to increase gradually as the coil-stretch transition proceeds. 

VCS Solution vapor pressure curve SC Solvent sublimation pressure curve... 

The first kind of isotherms characterizes the case of proportionality between the concentration in mobile phase and stationary phase such isotherms are usually encountered when the stationary phase is liquid and the component concentration is low. The phase diagrams for dissolution equilibrium shown in Figm e 2.4. give the following information (a) a linear dependence of partial pressure p, of the component on its mole fraction for ideal solutions (curve 1), according to the Eaoult law ... 

The type of correlation between experimentally measured variable parameters in the system is changing as a result of phase transformations within that system. The indirect methods are used to identify the changes in those correlations. For example, the p-V-T-x curves (pressure as a function of temperature (p-T curves) pressure or temperature as a function of volume (p-V or T-V curves) pressure drop during salt dissolution as a function of solution composition (p-x curves)) show a break at the location of the phase transformation. Not only pressure or temperature or composition could be considered as variables. The properties of the solution or the whole system itself as well as heating or cooling period in thermal analysis can be used as variables to find the phase transitions. 

FIG. 23 Dependencies of flow rate v on pressure difference AP for the D-8 solution/ air system in a hydrophobed quartz capillary, r = 5.25 pm, before (curves 1 and 2) and after equilibration with surfactant solution (curve 2). 

In Section 14-6 we examined the lowering of the vapor pressure of a solvent produced by a dissolved solute. Vapor pressure lowering is not measured as frequently as certain properties directly related to it. In Figure 14-23 the blue curves represent the vapor pressure, fusion, and sublimation curves in the phase diagram for a pure solvent. The red curves represent the vapor pressure and fusion curves of the solvent in a solution. The sublimation curve for the solid solvent that freezes from the solution is shown in purple. Two assumptions are implicit in Figure 14-23. One is that the solute is nonvolatile, the other is that the solid that freezes from a solution is pure solvent. For many mixtures, these requirements are easily met. ... 

Vapor Pressures of Solutions—The vapor pressure of a solution depends on the vapor pressures of its pure components. If the solution is ideal, Raoult s law (equation 14.3) can be used to calculate the solution vapor pressure. Liquid-vapor equilibrium curves showing either solution vapor pressures (Fig. 14-16) or solution boiling points (Fig. 14-17) as a function of solution composition... 

At z in the curve, however (the minimum of vapour pressure), the solution and vapour are in equilibrium and the liquid at this point will distil without any change in composition. The mixture at z is said to be azeotropic or a constant boiling mixture. The composition of the azeotropic mixture does vary with pressure. 

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