Coefficient Ostwald absorption

The solubility was expressed in terms of the Ostwald absorption coefficient, L, which is defined as the ratio of the volume of absorbed gas to the volume of absorbing liquid at the temperature and pressure of the measurement. This is because the Ostwald coefficient is really an equilibrium constant, and the method of correction to standard conditions does not need to be specified in comparison with the Bunsen coefficient. 

L = Ostwald absorption coefficient n = number of components in mixed salt x — mole fraction ot a component in mixed salt... 

In this section, we survey some of the outstanding properties of aqueous solutions of simple non-polar solutes such as argon, methane, and the like. [For an extensive review, see Battino and Clever (1966), Wilhelm and Battino (1973), Wilhem (1977), and Franks, Volume II 1973a.] The solubility of such solutes, as measured by the Ostwald absorption coefficient, is markedly smaller in water than in a typical organic liquid. (By typical or normal organic liquids, we mean alkanes, alkanols, benzene and its simple derivatives, etc.)... 

The Ostwald absorption coefficient is defined as the ratio of the number densities of a solute s in the liquid (/) and the gaseous... 

There exists a variety of other units by which solubility data may be reported these and the inter-conversion formulas are discussed in the literature [Hildebrand and Scott (1950), Friend and Adler (1957), Himmelblau (1959), and Battino and Clever (1966)]. In this chapter, we adhere to the application of the Ostwald absorption coefficient as a measure of the solubility. 

Table 3.1 shows some values of the Ostwald absorption coefficient y of argon in water and in some liquids. It should be noted that the solubility as measured by y is about an order of magnitude smaller in water compared with other solvents. Note, however, that the solubility of argon in ethylene glycol at 25°C is about 0.035, almost the same as in water Isee Ben-Naim (1968)]. 

Table 3.1. Ostwald Absorption Coefficient y for Argon in Water and in Some Organic Liquids at Two Temperatures ...

To convert Henry s constant //, to the Bunsen absorption coefficient Obu,/ the Ostwald absorption coefficient aos,i> the following relationship may be used... 

The solubility of a gas will always be given in terms of the Ostwald absorption coefficient. This is defined as follows Let be the volume of the gas (at a given T and P) dissolved in a given volume of liquid (at the same T and P). The Ostwald absorption coefficient is defined by... 

Fig. 7.1. Ostwald absorption coefficient (y X 10 ) for argon at 25°C in Hfi, DgO, and some alcohols, as a function of the molecular weight of the solvent. The anomalous low solubility in water is indicated by the vertical line connecting the experimental value with the extrapolated value. [Redrawn from Ben-Naim (1972e).]...

A. Solubility of Gases.1—This is usually expressed m one of two ways, namely, as Bunsen s Absorption Coefficient, ft, or as Ostwald s Solubility expression, l. These terms have already been defined (p. 36). 

The solubility of a gas in a liquid may be expressed by the Ostwald solubility coefficient, which is the volume of gas dissolved in unit volume of liquid at a given temperature, or as the Bunsen s absorption coefficient, in which the temperature and pressure are reduced to standard conditions. The solubility of a gas in a liquid decreases with increase of temperature at constant pressure and is directly proportional to pressure at a constant temperature (Henry s law). 

It will be seen from these tables that Henry s Law, when expressed in terms of the Ostwald coefficient k, holds over a much wider pressure range than when expressed in terms of k Up to 200 mm k remains constant within the limits of experimental error, and it will be observed, that at the same time the magnitude of the coefficient shows that the concentration of the dissolved gas becomes very considerable Using an empirical formula, Sackur and Stem have calculated with the aid of Hhese absorption coefficients the values of the osmotic pressure of the... 

Lannung (1930) gave solubility results for He, Ne, and Ar in water, methanol, ethanol, acetone, benzene, cyclohexane, and cyclohexanol for different temperatures from 5 to 45 C. He gave his results as the Bunsen absorption coefficient a. He gave the Ostwald coefficient L, where L = aT/273 and T is the r K of the measurement, but he defined L as the equilibrium ratio of the volume concentrations of the gas in the solution and in the vapor phase. ... 

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