Mole fraction water solubilities

Mole fraction water solubilities, Xk, are conveniently used in solubility-temperature and in multicomponent representations of solubility information. The mole fraction, Xk, of a component k in a system of m components is defined as... 

Oxygen + water. Battino s recommended four constant equation from an earlier work (5 ) was used to represent the low temperature (273-348 K) mole fraction oxygen solubility values. The data determined at the Battelle Memorial Institute laboratories in the early 1950 s (10,12) were used to estimate the one atmosphere oxygen pressure solubilities at higher temperatures. The data sets were combined in a linear regression to obtain the parameters of the three constant tentative equation for the solubility between 350 and 600 K (Table V, Figure 9). 

Mole fraction of component i in the liquid on tray j Solubility of water in hydrocarbon phase Mole fraction water... 

As mentioned earlier, it is important to pay particular attention to the purity of the ILs and gases in the solubility measurements, as impurities may have a large effect on the measured solubility. Water, for example, has a profound effect on many of the physical properties of ILs [12]. This is important as many ILs are extremely hygroscopic [3,12], [BMIMJIPFe] can absorb up to 0.16 mole fraction water from the atmosphere [3], In general, water in the IL causes a decrease in viscosity, while increases in viscosity have been attributed to halide content. Similarly, vrater and halide content both cause a decrease in density [3,12]. Thus, impurities can have a profound affect on the transport properties of the IL. As an example, gas solubility in gravimetric solubility measurements is affected by uncertainty in the IL density as propagated by the buoyancy correction. Particular attention should be paid to IL purity and all resulting impurities should be reported for the solubility measurements. 

Table 6.17 Mass fraction (w) and mole fraction (x) solubilities of water in RTILs and of RTILs in water and their n-octanol/water partition constants logP°w at ambient temperatures (specified in the references)... 

The solubility of hydrocarbon liquids from the same chemical family diminishes as the molecular weight increases. This effect is particularly sensitive thus in the paraffin series, the solubility expressed in mole fraction is divided by a factor of about five when the number of carbon atoms is increased by one. The result is that heavy paraffin solubilities are extremely small. The polynuclear aromatics have high solubilities in water which makes it difficult to eliminate them by steam stripping. 

In the case of three-phase equilibria, it is also necessary to account for the solubility of hydrocarbon gases in water. This solubility is proportional to the partial pressure of the hydrocarbon or, more precisely, to its partial fugacity in the vapor phase. The relation which ties the solubility expressed in mole fraction to the fugacity is the following ... 

As an example of the use of the nomograph, the line is shown which would be drawn to determine the solubility of n-hexane in water at 25°C. The coordinates given in Table 1 for normal paraffins have been used X = 15.0, Y = 20.0. The predicted solubility is 2 x 10 mole fraction The experimental value is 1.98 x 10as given by McAuliffe and Price. ... 

Most nonpolar substances have very small water solubilities. Petroleum, a mixture of hydrocarbons, spreads out in a thin film on the surface of a body of water rather than dissolving. The mole fraction of pentane, CsH12, in a saturated water solution is only 0.0001. These low solubilities are readily understood in terms of the structure of liquid water, which you will recall (Chapter 9) is strongly hydrogen-bonded. Dissimilar intermolecular forces between C5H12 (dispersion) and H2O (H bonds) lead to low solubility. 

The Henry s law constant for the solubility of radon in water at 30°C is 9.57 X 10-6 Mlmm Hg. Radon is present with other gases in a sample taken from an aquifer at 30°C. Radon has a mole fraction of 2.7 X 10-6 in the gaseous mixture. The gaseous mixture is shaken with water at a total pressure of 28 atm. Calculate the concentration of radon in the water. Express your answers using the following concentration units. 

Figure 3.1.1 The solubility of gaseous carbon dioxide in water as a function of both temperature and pressure. The CO2 solubility is expressed in terms of the mole fraction of carbon dioxide in the liquid solution.

PMBV was synthesized by a conventional radical polymerization. The monomer unit compositions of the PMBV were 0.64, 0.25, and 0.11 unit mole fractions for MPC, BMA, and VPBA, respectively. The number-averaged molecular weight and weight-averaged molecular weight were 6.2 x 104 and 6.5 x 104, respectively. This PMBV was completely water-soluble due to hydrophilic MPC units in the polymer. Figure 1 shows the chemical structure of PMBV. 

Fig. 18 Solubilities at 20°C of the two polymorphs of cimetidine, form A (<9>-) and form B (0), as a function of the mole fraction of 2-propanol in the 2-propanol/water system. Also shown are the solubility ratios (form A/form B) calculated at each solvent composition. (The data are adapted from Ref. 128.)...

Acetone is used as a solvent in a laboratory. There is some concern about the fire hazards associated with the acetone. One solution is to dilute the pure acetone with water, thus providing an increased flash point. What mole fraction of water in a water-acetone mixture is required to increase the flash point of the mixture to 100°F Acetone is completely soluble in water. 

The procedure of Beutier and Renon as well as the later on described method of Edwards, Maurer, Newman and Prausnitz ( 3) is an extension of an earlier work by Edwards, Newman and Prausnitz ( ). Beutier and Renon restrict their procedure to ternary systems NH3-CO2-H2O, NH3-H2S-H2O and NH3-S02 H20 but it may be expected that it is also useful for the complete multisolute system built up with these substances. The concentration range should be limited to mole fractions of water xw 0.7 a temperature range from 0 to 100 °C is recommended. Equilibrium constants for chemical reactions 1 to 9 are taken from literature (cf. Appendix II). Henry s constants are assumed to be independent of pressure numerical values were determined from solubility data of pure gaseous electrolytes in water (cf. Appendix II). The vapor phase is considered to behave like an ideal gas. The fugacity of pure water is replaced by the vapor pressure. For any molecular or ionic species i, except for water, the activity is expressed on the scale of molality m ... 

Figure 1. Solubility of the noble gases in water. Mole fraction solubility at 1 atm noble gas partial pressure vj. temperature. The curves are based on the equations...

Figure 2. Helium + water—mole fraction solubility at 1 atm helium partial pressure vs. temperature. At temperatures above 353 K (O) (6) ( , ) (1). The 590 K value of Wiebe and Gaddy was not included in the linear regression.

Figure 3. Neon + water—mole fraction solubility at 1 atm neon partial pressure...

Xenon + water. The solubility data of Potter and Clynne ((5) and of Stephan, Hatfield, Peoples and Pray (10 ) were used to estimate the mole fraction solubility at one atmosphere xenon pressure at the higher temperatures. The two sets of data were combined with the 20 solubilities selected from five papers by Battino (2) in a linear regression. Figure 6 shows the data, and Battino s equation and the three constant equation. The three constants for the tentative equation for use between the temperatures of 350 and 600 K are in Table V. The Stephan et al. solubility value at 574 K was not included in the regression. 

Hydrogen + water. Battino (4) selected 69 solu-bility values from nine papers that reported measurements between temperatures of 273 and 348 K. The mole fraction solubilities at one atmosphere partial pressure of hydrogen at the higher temperatures were estimated from the data of Wiebe and Gaddy (11), Pray, Schweichert, and Minnich (12 ), and Stephan, Hatfield, Peoples and Pray (1 ). The data from Pray, Schweichert and Minnich were combined with Battino s selected data in a linear regression to obtain the tentative four constant equation for the hydrogen solubility in water between 350 and 600 K (Figure 7 and Table V). 

Figure 8. Nitrogen + water—mole fraction solubility at 1 atm nitrogen partial pressure vj. temperature ( ) (10, 15, 16) (0) (12, 13, 14, 171 (values used in the...

A realistic boundary condition must account for the solubility of the gas in the mucus layer. Because ambient and most experimental concentrations of pollutant gases are very low, Henry s law (y Hx) can be used to relate the gas- and liquid-phase concentrations of the pollutant gas at equilibrium. Here y is the partial pressure of the pollutant in the gas phase expressed as a mole fraction at a total pressure of 1 atm x is the mole fraction of absorbed gas in the liquid and H is the Henry s law constant. Gases with high solubilities have low H value. When experimental data for solubility in lung fluid are unavailable, the Henry s law constant for the gas in water at 37 C can be used (see Table 7-1). Gas-absorption experiments in airway models lined with water-saturated filter paper gave results for the general sites of uptake of sulfur dioxide... 

Source Detected in distilled water-soluble fractions of 87 octane gasoline (24.0 mg/L), 94 octane gasoline (80.7 mg/L), Gasohol (32.3 mg/L), No. 2 fuel oil (0.50 mg/L), jet fuel A (0.23 mg/L), diesel fuel (0.28 mg/L), militaryjet fuel JP-4 (17.6 mg/L) (Potter, 1996), new motor oil (0.37-0.40 jg/L), and used motor oil (195-198 Jg/L) (Chen et ah, 1994). Diesel fuel obtained from a service station in Schlieren, Switzerland contained benzene at a concentration of 76 mg/L (Schluep et al, 2001). The average volume percent and estimated mole fraction in American Petroleum Institute PS-6 gasoline were 2.082 and 0.2969, respectively (Poulsen et al, 1992). Schauer et al. (1999) reported benzene in a diesel-powered medium-duty truck exhaust at an emission rate of 2,740 pg/km. 

If Z9b(ai) can be equated with P calculated from the entries in Table 2.5, then Z9b(a2) in any other solvent Ab can be estimated from Eq. (2.62). Equation (2.62) is actually a combination of four expressions of the form of Eq. (2.8) (see section 2.2.2), two for water and solvent Ai and two for water and solvent A2, presuming them to be immiscible pairs of liquids. It employs concentrations on the mole fraction scale, and assumes that the systems behave as regular solutions (which they hardly do). This eliminates the use of the solubility parameter 8 of water, which is a troublesome quantity (see Table 2.1). Solvent Ai need not, of course, be 1-octanol for Eq. (2.62) to be employed, and it suggests the general trends encountered if different solvents are used in solvent extraction. 

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