Ostwald coefficient

At equilibrium, the concentration in the blood is depicted by the formula (also known as the Ostwald coefficient) XhjX.A = S, where Xh is the concentration in the blood and X i is the concentration in the inspired air. Thus, if one knows the S for a given chemical and the target concentration for a given exposure, one can predict what the resulting concentration may be at equilibrium. Additionally, the lower the S value (i.e., the lower the solubility in blood) the more rapidly the chemical will achieve equilibrium. 

Ostwald coefficient physchem A measure of the solubility of a gas in a liquid, equal to the volume of gas that can be dissolved in a given volume of liquid divided by the volume of liquid. ast.valt, ko-3,fish-ant ... 

The Ostwald coefficient Lg is the ratio between volume of adsorbed gas and volume of solvent, measured at the same temperature ... 

The volume in milliliters of gas dissolved per milliliter of liquid at one atmosphere of partial pressure of the gas at any given temperature. Thus, the Ostwald coefficient (A) differs from the Bunsen solubility coefficient (a) which is based on standard temperature and pressure. The two coefficients are related by the equation A = a(l + 0.00367t) where t is the temperature in degrees Celsius. 

Gas solubilities may be expressed as (1) volume of gas dissolved in unit volume of solvent, known as the Ostwald coefficient, designated by r ... 

Kamlet-Taft) electron pair donation ability Ostwald coefficient (for gas solubility) mean ionic activity coefficient... 

Other measures of the solubility of a gaseous solute are readily derived from its mole fraction. The Henry s law constant is KH lim(pjxj30) atp2 —> 0, which becomes on the molal scale Km lim(1000 p2/Mjc2) with Mj the molar mass of the solvent in g mob1 for use in Eq. (2.13) below. The Ostwald coefficient is the limit of y2 = RT(xJp lVl atp2 -> 0 and is related to the mass fraction w2 by ... 

L21, Ostwald coefficient 288-303 K, latm partial pressure 4... 

The units used to express solubilities of gases, e.g. Henry s law coefficients, Ostwald coefficients and Bunsen coefficients, have to be converted to the relevant solution standard state (p. 213). Such solubilities (Battino and Clever, 1966 Wilhelm and Battino, 1973) are valuable in the analysis of kinetic data. For example, the solubility of a neutral solute in a range of aqueous mixtures can provide some indication of the variation of the chemical potential of a neutral reactant because, from eqn (11), 8m AGe = 8mnf. Where the pure solute is a liquid or solid, it is often convenient to chose the pure solute as a standard state, represented by the symbol, ° in eqn (12). Similar comments apply to the related thermodynamic quan-... 

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. 

The reliability and accuracy of the experimental apparatus and procedure were determined by the measurement of the solubility of carbon dioxide in pure water. The average value of the Ostwald coefficient, L0, obtained in this work was 0.8264 and agreed quite well with values in the literature (12). 

The Ostwald coefficient is the ratio of the volume of gas absorbed to the volume of the absorbing liquid, both measured at the same temperature [8]. 

The experimental Ostwald coefficients [4,5] were converted into the Henry constants. The molar volumes of the aqueous solutions of PPG-400, PEG-200 and PEG-400 were calculated from experimental densities [4,5] to conclude that they are well approximated by the expression... 

In anaesthetic practice, an alternative solubility coefficient, the Ostwald solubility coefficient, is preferred. This coefficient is defined as the volume of gas which dissolves in a unit volume of the liquid at the given temperature. The volume of gas is not corrected to standard temperature and pressure but instead is measured at the temperature and pressure concerned. The important difference between these two coefficients is that the Ostwald coefficient is independent of pressure, as we can see from the following example. 

Anaesthetic gases such as ether which have a high blood solubility (Ostwald solubility coefficient in blood is 12) are transported away from the lungs more rapidly than those such as halothane (Ostwald coefficient = 2.3) and nitrous oxide (Ostwald coefficient = 0.47). As... 

TABLE 23. OSTWALD COEFFICIENTS (Z)/L OF O2AT latm IN AQUEOUS SOLUTIONS AT 25 C ... 

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... 

An older variation of this term is the Ostwald coefficient, which uses the gas volume at actual conditions instead of at standard conditions.) In general nse today is the Henry s law coefficient, H. ... 

Some variation in rate constants obtained by different research groups can be attributed to use of different references for the solubility of O2 in the solvents employed, or even to incorrect application of Bunsen or Ostwald coefficients in the calculation of [O2I. Since the atmospheric pressure, the temperature, and the degree of humidity when measurements were made in the presence of air are usually not reported, correction of the rate constants by application of uniform O2 concentrations is difficult. It will nonedteless be attempted when necessary, using a recently published critical and comprehensive compilation of Oj solubility data (16). 

The solubility of gases is generally described by the Ostwald coefficient L = Vs/Tw, where subscripts s and w denote the solute and the solvent (water), and Vs denotes the volume of pure gas at a given temperature and pressure sorbed by (dissolved in) a volume Vw of pure water. For the standard pressure of =0.1 MPa 1 atm (the Ostwald coefficient is not appreciably dependent on the pressure at moderate pressures) the standard state molar volume of the gas is Vs° =RT/P° + Bss, the second term is the second virial coefficient of the gas (describing interactions of the gas molecules with each other) and generally Bss RT/P° and can be ignored. The molar concentration (in Vw = 1 dm of water) of the gas is then LP°IRT (with... 

This work, on the other hand, is empirically related to the Ostwald coefficient Lsw for the solubility of the organic liquid as a gaseous solute in water, Lsw = cs-in-w/cs-gas. 

The first is the Bunsen coefficient (P), which is the ratio of the volrrme of gas corrected to STP (0°C and latm, i.e. 760 mmHg) that dissolves in imit volrrme of solvent at the terrrperature of the experiment in equilibrium with the gas at latm. The second is the Ostwald coefficient (/) which is the ratio of the volume of gas that dissolves in unit volume of solvent at the temperatirre of the experiment in eqttiltbrirrm with the gas at latm. 

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