activity coefficient


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activity coefficient

[‚ak′tiv·əd·ē ‚kō·ə′fish·ənt]
(physical chemistry)
A characteristic of a quantity expressing the deviation of a solution from ideal thermodynamic behavior; often used in connection with electrolytes.
References in periodicals archive ?
In order to calculate the liquid phase activity coefficients the Margules-1-suffix model was used.
The Cd activity coefficient was calculated for a rather low soil solution concentration, but even at this concentration of the solution the influence of the ion association was significant.
The authors demonstrated that the activity coefficient of carbon dioxide is considerably higher in the methanol-carbon dioxide mixture, and that the non-linearity of the liquid phase is due to the auto association present in methanol (as they suggested).
Activity Coefficients. For activity coefficients, Pitzer model [11] was successfully used in gas-water-mineral modeling for high salinities in previous works [12-15].
where [[gamma].sup.k] indicates the activity coefficient; [m.sub.k] is the molality; [A.sub.[gamma]], [B.sub.[gamma]], and [??] are temperature-dependent coefficients; I indicates the ionic strength; [[??].sub.k] is the ion size parameter; and [z.sub.k] represents the ionic charge.
The relation between the mass-based infinite dilution activity coefficient of the solvent, ([[OMEGA].sub.13.sup.[infinity]]), and its retention volume ([V.sub.g,i]), in a solvent (1)-polymer (3) mixture, is given by Eq.
So the traffic operation state has a relatively larger average external transition probability and activity coefficient and a smaller stability and attractiveness coefficient.
To calculate the solubility of the diatomic gases in the multicomponent metallic systems, it is necessary to determine the activity coefficients of these gases.
The equation to determine activity from the activity coefficient and the concentration is:
Where, [H.sup.+] is the concentration of the hydrogen ions [mol/liter] and [f.sub.H] is the activity coefficient of the hydrogen ions.
In order to have an understanding of those chemically reacting, multi-component, multiphase systems, a brief discussion about the chemical equilibria, vapour--liquid phase equilibria, thermodynamic framework, and activity coefficient model are included, which ensures an appropriate formulation of the objective function.