Vapor pressure diagram

The Hausbrand vapor-pressure diagram [127, 128] in Figure 8-40 is a useful approach for the steam distillation calculation. This particular diagram was prepared for six organic compounds and the corresponding water vapor pressure as (it - ps) for three system pressures of 760, 300, and 70 mm Hg versus temperature,... 

Figure 8-40. Hausbrand vapor-pressure diagram for various liquids and at three system steam pressures. A similar diagram can be constructed for other organic/hydrocarbon systems. Used by permission, Ellerbee, R. W., Chem. Eng. Mar. 4 (1974), p. 108.

The equilibrium vapor pressure (ps) can be measured by the barometric temperature measurement (BTM) and be converted into temperature by the water vapor pressure diagram (see Section 1.2.3). 

Fig. 2.4 The vapor pressure diagram of a dilute solution of the solute B in the solvent A. The region of ideal dilute solutions, where Raoult s and Henry s laws are obeyed by the solvent and solute, respectively, is indicated. Deviations from the ideal at higher concentrations of the solute are shown. (From Ref. 3.)...

Figure 3 Vapor-pressure diagram of benzene-toluene solutions.

The vapor pressure of such a solution varies linearly with xB from Pi to PB. This behavior is illustrated in the vapor-pressure diagram of benzene-toluene solutions shown in Fig. 3. 

Figure 5 Ethyl ether-ethyl alcohol vapor-pressure diagram at 50°C. (Data from J Timmermans. Physiochemical Constants of Binary Systems in Concentrated Solutions. Volume 2. New York Interscience, 1960, p 401.)...

Figure 8 Acetone-chloroform vapor pressure diagram at 35.2°C. (Data from Example 1.)...

Note that Fig. 3.14.3 is also representable as a vapor pressure diagram of P /P versus xi. This is so because when equilibrium prevails /x + RT na =... 

Effect of impurities on the melting point. The student will recall that a substance in either the solid or liquid form exerts a definite vapor pressure and that this pressure increases with the temperature. It will also be recalled from the vapor-pressure diagram of water that at 0° C. the vapor pressure of ice (solid) and of water (liquid) are the same (4.5 mm of mercury). Figure 13 represents the vapor pressure of naphthalene. At 80° the vapor pressures of both liquid and solid are the same. The rate of transformation of solid naphthalene to liquid at 80° equals the rate of transformation of liquid naphthalene to solid. Below 80° the transformation of liquid naphthalene to solid proceeds faster than that from the solid to liquid, and the substance solidifies. Above 80° the vapor pressure... 

Use the following vapor pressure diagram to estimate (a) the partial pressure of chloroform, (b) the partial pressure of acetone, and (c) the total vapor pressure of a solution in which the mole fraction of CHCI3 is 0.30, assuming ideal behavior. 

A system which is close to ideal in its behavior is a solution of benzene and toluene. These molecules are very similar in structure so that the intermolecular forces between benzene and toluene do not dilfer greatly from those between benzene molecules or toluene molecules in each pure liquid. The vapor pressure diagram for this system at 25°C is shown in fig. 1.4. Since toluene has a higher molecular weight, its vapor pressure as a pure liquid is lower (3.25 kPa) than that of benzene (12.69 kPa). The total vapor pressure Pj is obtained by adding those of components A and B, so that... 

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. 

Vapor Pressure Diagrams At a certain temperature, and in equilibrium, a saturation vapor pressure of T) develops over an easily evaporating liquid A (compare Sect. 12.5). (The symbol indicates again that the quantity refers to a pure phase.) In order to avoid an unattractive piling up of indices, we will use p in the following. If an easily evaporating substance B is dissolved in A (Fig. 14.13), the chemical potential of A decreases as a result of dilution. 

Fig. 14.15 Vapor pressure diagram of a system of two largely indifferent components A and B (at constant temperature).

Fig. 14.16 Applying the lever rule in a vapor pressure diagram.

F. 14.21 (a) Vapor pressure diagram with azeotropic minimiun of a binary system of two highly compatible substances, (b) Corresponding boiling point diagram with azeotropic maximum. 

A simple vapor pressure diagram with the possibility for extrapolation is given by Hoffmann and Florin and is shown in Fig. 2.1-2. For many systems the modified temperature scale 1 / r obeys the relation... 

Match the vapor pressure diagrams with the solute-solvent combinations and explain your answers. 

Figure 8.2 The vapor pressure diagram of a perfect binary solution for...

Figure 8.3 The vapor pressure diagram of a binary solution. When the mole fraction is very small or nearly equal to one, we have ideal behavior.

Binary vapor-liquid equilibria of ideal systems (a) boiling-point diagram (b) vapor-pressure diagram (c) x-y diagram. 

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