Activity coefficient of strong electrolytes

Meissner, H. P. and C. L. Kusik, "Activity Coefficients of Strong Electrolytes in Multicomponent Aqueous Solutions," AIChE J., 1972, 18, 294. 

Meissner, H.P. "Prediction of Activity Coefficients of Strong Electrolytes in Aqueous Systems," paper presented at symposium on "Thermodynamics of Aqueous Systems with Industrial Application," Washington, D.C., October 22-25,... 

Hamer, W. J. "Theoretical Mean Activity Coefficients of Strong Electrolytes in Aqueous Solution from 0 to 100 C" NSRDS-NBS 24, U.S. Department of Commerce, National Bureau of Standards, December 1968. 

Prediction of Activity Coefficients of Strong Electrolytes in Aqueous Systems... 

Meissner Tester, "Activity Coefficients of Strong Electrolytes in Aqueous Solutions", I EC Process Design and Development, vol 11, p 128, (1972)... 

The original form of the Debye-Hiickel equation permits the calculation of the mean activity coefficients of strong electrolytes in solutions defined by their molarity c. Should the value of this coefficient be expressed by molality, whioh is more advantageous in electrochemistry, it will be possible in the case of a sufficiently diluted solution to substitute into the equation (V-58) for = y m (see V-41e) and for molarities of all ions the product of their molalities and the density of the solvent s wqp°, so that ... 

EXPERIMENTAL DETERMINATION OF ACTIVITIES AND ACTIVITY COEFFICIENTS OF STRONG ELECTROLYTES... 

Experimental Determination of Activities and Activity Coefficients of Strong Electrolytes... 

In the experimental determination of activity coefficients of strong electrolytes, by the methods described below, the molalities, etc., of the ions are taken as the stoichiometric values, that is, the total possible molality, etc., disregarding incomplete dissociation, For example, in the last problem, the molalities of the sodium and sulfate ions in the 0.5 molal solution of sodium sulfate were taken as exactly 1.0 and 0.5, respectively, without allowing for the possibility that the salt may be only partially dissociated at the specified concentration. The activity coefficients obtained in this manner are called stoichiometric activity coefficients they allow for all variations from the postulated ideal behavior, including that due to incomplete dissociation. If the treatment is based on the actiuil ionic molalities, etc., in the given solution, as in the Debye-Httckel theory (Chapter XVII), there is obtained the true (or actual) activity coefficient. TTie ratio... 

Eq. (B.l) will allow fairly accurate estimates of the aetivity coefficients in mixtures of electrolytes if the ion interaction coefficients are known. Ion interaction coefficients for simple ions can be obtained from tabulated data of mean activity coefficients of strong electrolytes or from the corresponding osmotic coefficients. Ion interaction coefficients for complexes can either be estimated from the charge and size of the ion or determined experimentally from the variation of the equilibrium constant with the ionic strength. 

Mean ionic activity coefficients of strong electrolytes... 

Meissner, H.P. and Tester, J.W. (1972) Activity coefficients of strong electrolytes in aqueous solution. Industrial and Engineering Chemistry, Process Design and Development, 11, 128-133. 

Diamond RM (1958) Activity coefficients of strong electrolytes, the hahde salts J Am Chem Soc 80 48084812... 

TABLE 29.1. Activity Coefficients of Strong Electrolytes M = molality)... 

After expansion and refinement of the original method (M4,M6,M8), including an expansion for handling multicomponent systems which will be discussed in the next chapter (M2,MS,M9), a useful method for predicting the activity coefficients of strong electrolytes over a range of temperatures and ionic strengths was presented (M7,M10). 

Meissner and Kusik (M2) presented, in 1972, a method of calculating the reduced activity coefficients of strong electrolytes in a multicomponent solution. They based their method on Br0nsted s proposal that, in multicomponent solutions, the activity coefficient of an electrolyte will be influenced most by the interaction of it s cation with all the anions in solution and the interaction of it s anion with all the cations in solution. Ignoring the possible interactions between like charged ions was felt to be valid as such interactions would be very small. Meissner and Kusik proposed that the activity coefficient could then be defined as ... 

Use of the Meissner family of curves as presented in Chapter IV, Figure (4.6), in order to correlate the reduced activity coefficients of strong electrolytes. Meissner found that the reduced activity coefficients of strong electrolytes fell into a pattern which he formalized. If it can be assumed that the reduced activity coefficients of strong electrolytes follow this pattern, then deviation from these curves may be said to indicate that the species in question does not completely dissociate or may be forming complexes. If activity coefficients from experimental data are available they may be plotted on the Meissner chart. Severe deviation from the curves, such as the crossing of lines, may be taken to indicate complex formation. However, there would be no indication of what the complexes might be. 

W. J. Hamer, Theoretical Mean Activity Coefficients of Strong Electrolytes in Aqueous Solutions from 0 to 100°C, NBS No. 24, U. S. Government Printing Office, Washington, D. C., 1968. 

Gilbert N. Lewis and Merle Randall, The Activity Coefficient of Strong Electrolytes. J. Am. Chem. Soc., 1112-1154(1921). 

In order to obtain more accurate results, it is preferable to use cells with no junction, but in that case, the method of measuring the activity coefficients of strong electrolytes will yield only the mean activity coefficient. 

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