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Raoult mixture

Figure 5 shows the isothermal data of Edwards (1962) for n-hexane and nitroethane. This system also exhibits positive deviations from Raoult s law however, these deviations are much larger than those shown in Figure 4. At 45°C the mixture shown in Figure 5 is only 15° above its critical solution temperature. Again, representation with the UNIQUAC equation is excellent. Figure 5 shows the isothermal data of Edwards (1962) for n-hexane and nitroethane. This system also exhibits positive deviations from Raoult s law however, these deviations are much larger than those shown in Figure 4. At 45°C the mixture shown in Figure 5 is only 15° above its critical solution temperature. Again, representation with the UNIQUAC equation is excellent.
Let us consider a mixture forming an ideal solution, that is, an ideal liquid pair. Applying Raoult s law to the two volatile components A and B, we have ... [Pg.6]

In equation 21 the vapor phase is considered to be ideal, and all nonideaHty effects are attributed to the Hquid-phase activity coefficient, y. For an ideal solution (7 = 1), equation 21 becomes Raoult s law for the partial pressure,exerted by the Hquid mixture ... [Pg.235]

In most cases, systems deviate to a greater or lesser extent from Raoult s law, and vapour pressures may be greater or less than the values calculated. In extreme cases (e.g. azeotropes), vapour pressure-composition curves pass through maxima or minima, so that attempts at fractional distillation lead finally to the separation of a constantboiling (azeotropic) mixture and one (but not both) of the pure species if either of the latter is present in excess. [Pg.9]

Raoult s law States that at equilibrium, the partial pressure of a solute vapor over a liquid mixture is equal to the vapor pressure of the pure solute at the given temperature times the mole fraction of the solute liquid component in the mixture. [Pg.1471]

Some organic compounds can be in solution with water and the mixture may still be a flammable mixture. The vapors above these mixtures such as ethanol, methanol, or acetone can form flammable mixtures with air. Bodurtha [39] and Albaugh and Pratt [47] discuss the use of Raoult s law (activity coefficients) in evaluating the effects. Figures 7-52A and B illustrate the vapor-liquid data for ethyl alcohol and the flash point of various concentrations, the shaded area of flammability limits, and the UEL. Note that some of the plots are calculated and bear experimental data verification. [Pg.496]

When one liquid is dissolved (totally miscible) in another, the partial pressure of each is decreased. Raoult s Law states that for any mixture the partial pressure of any component will equal the vapor pressure of that component in the pure state times its mol fraction in the liquid mixture. [Pg.2]

There are many mixtures of liquids that do not follow Raoult s Law, which represents the performance of ideal mixtures. For those systems following the ideal gas law and Raoult s Law for the liquid, for each component. [Pg.2]

Raoult s Law is not applicable as the conditions approach critical, and for hydrocarbon mixtures accuracy is lost above about 60 psig [81]. [Pg.3]

Therefore, for Raoult s and Dalton s Lavsrs to apply, the relationship between the vapor and liquid composition for a given component of a mixture is a function only of pressure and temperature, and independent of the other components in the mixture. [Pg.3]

Fugacity in Liquid Mixtures Raoult s Law and Henry s Law Each component in a liquid mixture has an equilibrium vapor pressure, and hence, a vapor fugacity. These fugacities are functions of the composition and the nature of the components, with the total vapor fugacity equal to the sum of the fugacities of the components, That is,... [Pg.268]

Equation (6.79) relates the slopes of the vapor pressure lines in a graph of vapor pressure against mole fraction such as those shown in Figures 6.5 to 6.8. It requires that if one of the components in a binary mixture obeys Raoult s law over the entire composition range, then the other must do the same. This can be seen as follows. If component 1 obeys Raoult s law over the entire composition range, then the slope of the graph of p against is... [Pg.277]

Therefore, it is a sufficient condition for ideal solution behavior in a binary mixture that one component obeys Raoult s law over the entire composition range, since the other component must do the same. [Pg.277]

For liquid mixtures (especially when the components are nonelectrolytes) in which we work with solutions over the entire range of composition, we often choose the Raoult s law standard state for both components. Thus, for the second component... [Pg.289]

Figure 6.12 shows a graph of u and a2 as a function of mole fraction for mixtures of. yi H O +. Y2CCI4J12 at T = 308.15 K.. A Raoult s law standard state has been chosen for both components. The system shows negative deviation from Raoult s law over the entire range of composition, with it less than. Y and a2 less than. V2. so that all -r.i and 7R.2 are less than 1. [Pg.289]

A Raoult s law standard state for the solute is often chosen for nonelectrolyte mixtures that cover the entire concentration range from. v — 0 to. Vi = 1 ... [Pg.293]

For a mixture containing volatile components, the activities of both components (usually based on a Raoult s law standard state) can be obtained by measuring the total vapor pressure p above the mixture, the composition of... [Pg.304]

Thus, with a Henry s law standard state, H° is the enthalpy in an infinitely dilute solution. For mixtures, in which we choose a Raoult s law standard state for the solvent and a Henry s law standard state for the solute, we can... [Pg.351]

Equations (7.93) and (7.94) are usually applied to mixtures of nonelectrolytes where Raoult s law standard states are chosen for both components. For these mixtures, Hi is often expressed as a function of mole fraction by the Redlich-Kister equation given by equation (5.40). That is... [Pg.362]

Figure 8.17 Vapor fugacity for component 2 in a liquid mixture. At temperature T, large positive deviations from Raoult s law occur. At a lower temperature, the vapor fugacity curve goes through a point of inflection (point c), which becomes a critical point known as the upper critical end point (UCEP). The temperature Tc at which this happens is known as the upper critical solution temperature (UCST). At temperatures less than Tc, the mixture separates into two phases with compositions given by points a and b. Component 1 would show similar behavior, with a point of inflection in the f against X2 curve at Tc, and a discontinuity at 7V... Figure 8.17 Vapor fugacity for component 2 in a liquid mixture. At temperature T, large positive deviations from Raoult s law occur. At a lower temperature, the vapor fugacity curve goes through a point of inflection (point c), which becomes a critical point known as the upper critical end point (UCEP). The temperature Tc at which this happens is known as the upper critical solution temperature (UCST). At temperatures less than Tc, the mixture separates into two phases with compositions given by points a and b. Component 1 would show similar behavior, with a point of inflection in the f against X2 curve at Tc, and a discontinuity at 7V...
Since Raoult s law activities become mole fractions in ideal solutions, a simple substitution of.Y, — a, into equation (6.161) yields an equation that can be applied to (solid + liquid) equilibrium where the liquid mixtures are ideal. The result is... [Pg.419]

FIGURE 8.35 The vapor pressures of the two components of an ideal binary mixture obey Raoult s law. The total vapor pressure is the sum of the two partial vapor pressures (Dalton s law). The insets below the graph represent the mole fraction of A. [Pg.459]

Consider an ideal binary mixture of the volatile liquids A and B. We could think of A as benzene, C6H6, and B as toluene (methylbenzene, C6H< CH ), for example, because these two compounds have similar molecular structures and so form nearly ideal solutions. Because the mixture can be treated as ideal, each component has a vapor pressure given by Raoult s law ... [Pg.459]


See other pages where Raoult mixture is mentioned: [Pg.214]    [Pg.653]    [Pg.7]    [Pg.179]    [Pg.237]    [Pg.252]    [Pg.598]    [Pg.1259]    [Pg.1293]    [Pg.9]    [Pg.164]    [Pg.347]    [Pg.348]    [Pg.80]    [Pg.294]    [Pg.268]    [Pg.270]    [Pg.271]    [Pg.276]    [Pg.293]    [Pg.293]    [Pg.330]    [Pg.331]    [Pg.369]    [Pg.413]    [Pg.855]   
See also in sourсe #XX -- [ Pg.37 ]




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