Handbook of aqueous electrolyte thermodynamics theory application

American Chemical Society, Organic Compounds. Na H c1. I Mei ssner H 2. Multicomponent Strong Electrolytes H,O NaOH. Multicomponent Strong Electrolytes Temperature: Method: Multtcomponent Strong Electrolyte8 Temperature: Method: PZ, P3, P4 also presented an extended form of the Pitzer equation for use with aqueous molecular solutes.

Ji I] with triple interactions between ions all having the same sign ignored VII. Weak Electmlpter and Moleaular Speclea Chen et al.

X a m Aa'm a To describe t h e difference in the interactions of a molecular solute with two salts having the same cation. The disregard of the ternary ion-molecule interactions was based on the approximate additivity of the contributions made by ions from inorganic salts; Chen notes that organic ion contributions do not show this additivity so that t h e ternary ion-molecule interactions in organic salt solutions should not be ignored. The appropriate derivatives of equation 7.

W e a k BlcctmIytee and M o l e c u l a r Spedee Prediutione Based Upon Theoretical Equations The theoretical equations given by Setschenow and Pitzer can be evaluated based upon an extensive body of published data on a large number of binary and ternary systems involving weak electrolytes. Newrnan and Prausnitz and of Beutier and Renon. Comparisons of predicted and experimentally measured total pressure and partial pressure s a r e presented in both tabular and graphical form.

In the case of the last example wherein NaCl is present, the emphasis will be on prediction using the S etsch6now equation and comparison to resonable published data. The tabular and graphical output will, in every case, reference both: 1 The method used 2 The source of the data - Ammonia Water Figures 7. The - species considered in the predictive model are N H 3 aq. HpO aq. Weak Electrolytee and Molecular Specie8 F i g u r e 7.

Weak Electrolytes and Molecular Species Figure 7. Ammonia - Carbon Dioxide - Water - Figures 7. The species considered in the predictive model a r e N H 3 as , NH?.

N H 2CO5. Oxygen - Sodium Chloride - Water Figures 7. Conclusions Using the published Pitzer coefficients and applying them to the binary systems NH3-H20, C 0 2 - H 2 0 and SH20, resulted in 1 An excellent match between the predicted points and the experimental data over the entire range for the CH20 system.

One likely reason for the poor fit at high concentrations is found in the material discussed in Chapter VI. L Ln 4 pC02 exp. Weak Electrolytee and Molecular Speclee Figure 7. C Oxygen solubility in ppm in sodium chloride concentrations of: 0. Once again we see that at high concentrations intermediates complexes are the key to accurate simulation. This is not surprising since NHsOH aq was not considered.

In addition to the scatter, several published points could not even be I t appears that from a numerical point of view, the activity coeffisimulated. This could be due to a number of factors such a s a typographical error in one of the published interaction values. Since the numerical problems did not occur for either of the constituent binary systems, it would have to be an error in one of the crossover terms such as any NHzCOZ interaction.

Using the Setschihow equation on the oxygen-sodium chloride-water system resulted Nonetheless, the trend of solubility of oxygen with in a fairly poor fit. McDevit, "Activity coefficients of nonelectrolyte solutes in aqueous salt solutions", Chem. I , pp87, 88 and "Correction", Ind. OO NaBr 0. W e a k Electrolytes 8nd Moleuula? Evans; V. Parker; I. Halow; S. Bailey; R. Parker; 1. Schumm; K. Wagman and W. Wagman; S. Bailey; W. Parker; R. Schumm; R. Parker, R.

Schumm, 1. Halow, S. Churney, R. Data, v l l , suppl. Moscow - 0,H , b Volume I1 - S. Nb, Ta, Ti. Zr, Hf Y, La, Ce. Bk, Cf, Es, Fm. Helgeson, H. Kirkham, "Theoretical Prediction of the Thermodynamic 1. Hdgeson, H. Kirkham, "Theoretical Prediction of the Thermodynamic Kirkham, G.

Wilhelm, E. Battino, R. Mackay, W. Shiu, "Solubility of hexane. J Chem. Data, v Armenante, P. Bromley, L. Cysewski, G. Prausnitz, "Estimation of gas solubilities in polar and nonpolar solvents", Ind. Desnoyers, J.

Billon, S. Leger, G. J-P Morel, "Salting out of alcohols by alkali halides at the freezing temperature", J. Furter, W. Thorne, "Salt effects on the activity coefficient of Gordon, J. Mixtures of two salts", J. Thorne, "Salt effects on non-electrolyte activity Gordon. Artificial and coefficients in mixed aqueous electrolyte solutions. Wiley L Sons, Gordon, J. New York JACS, v48, p S l l. Himmelblau, D. Khomutov, N. Konnik, "Solubility of oxygen in aqueous electrolyte solutions", Russ. K rishnan, C.

Friedman, "Model calculations coefficients", J. U9, pp McDevit, "Activity coefficients of nonelectrolyte solutes in S Long, F. Masterton, W. P Lee, "Salting coefficients from scaled particle theory", J. Bolocofsky, T. Lee, "Ionic radii from scaled particle theory of the salt effect".

Polizzotti, H. Welles, "The eolubility of argon in aqueous solutions of a complex-ion electrolyte", J. Masterson, scaled-particle theory". McDevit, W. Long, "The activity coefficient of benzene in aqueous salt Bolutions". The effect of S Morrison, T. Billet, "The salting-out of non-electrolytes. Part The effect of variation in non-electrolyte", J. Onda, K. Saka, T. Kobayashi, S. Ito, "Salting-out parameters of gas solubility in aqueous salt solutions", J. Japan, v3, 1, pp S Pawlikowski, E.

Prausnitz, "Estimation of Setchenow constants for nonpolar gases in common salts at moderate temperatures", Ind. Prausnitz, "Correction". Prausnitz, J. Randall, M. Randall, correlation of , gas McBain. White, JACS. Failey, "The activity coefficients of gases in aqueous salt solutions", Chem. The salting-out order of the ions", Chem. Failey, "The activity coefficient of the undissociated part of weak electrolytes", Chem. Adler, W. Deckwer, "Solubility of oxygen in electrolyte solutions".

Sergeeva, V. Setschehow, J. Weak Eleutrolytee and Yolwular Spedes K. Gubbins, "Solubility of nonpolar gases in concentrated electrolyte solutions". Shoor, S.

Tiepel, E W. E Gubbins, "Thermodynamic properties of gases dissolved in electrolyte solutions", Ind. Battino, "Thermodynamic functions of the solubilities of gases in liquids at 25OC". Yasunishi, A. Japan, v10, 2 , pp S Yen, L.

McKetta, J r. AIChE J. Beutier, D. Process Des. Renon, "Corrections", Ind. Chen, C-C; H. Boston, L. Britt, J.

C-C; H. Newman ed.. ACS Syrnp. Series , pp b. Thermodynamics Series Suppl. ACS Symp. Edwards, T. Newman, J. Maurer, J. Pottel, R. Franks ed. Renon, H. Newman ed. Series Suppl. Hunter, "The system ammonia-water a t temperatures up to 15OOC and a t p r e s s u r e s up to twenty atmospheres", J. Eakin, R. ElIington, J. Huebler, "Physical and Macriss, R. McLean, P. Ritchie, "Compressibility, fugacity. Johnstone, H. T h e ionization constant and heat of ionization of sulfurous acid".

Cramer, S. In general, this is an area which has received very little attention in the literature. Specifically, the properties to be considered are density and enthalpy. The treatment of these two distinct properties herein should serve to suggest the manner in which such properties can be approached. In the case of density the approach is similar to that taken w i t h respect to the calculation of activity coefficients in a multicomponent solution.

The approach for enthalpy in. The enthalpy of a solution is composed of contributions from each constituent species in the solution. Each species contributes a pure component enthalpy term and an "excess enthalpy" term. This latter term is based upon the derivative of the species' activity coefficient with respect to temperature. Each of these properties will now be considered in more detail. To begin with we will consider a general solution made up of water plus one or more salts in solution.

Once this b accomplished, a reasonable mixing rule for multicomponent systems can be proposed. Thermodynamic Functions with the subscript 1 denoting water and the subscript 2 indicating the electrolyte.

By this definition, we can see that the apparent molal volume of an electrolyte in a binary system is the difference between the total solution volume and the volume of water in the solution divided by the number of moles of the electrolyte present. Vi0 is defined a s the partial molal volume of pure water a t the solution temperature.

This can be expressed as: - - M1 Y. Density variations are often small and thus must be measured with considerable When using such accuracy.

Reference t o K e l l 18 will facilitate these conversions. The unknown coefficients of equation 8. Strong Electrolytes Which Complex The above treatment applies directly to strong electrolytes which completely dissociate t o their constituent ions.

The factor W in equation 8. In Chapter VI. Thermodynamic Functions 8. Weak Electrolytes The problem highlighted in Case 3 above becomes even more significant in the case of weak electrolytes. This can be seen, in the case of COz.

The total ionic strength is thus obtained only In order to handle weak electrolytes and still utilize the above framework, i t would be necessary to: 1 Obtain good density data for the binary e. H , O - C O , 2 Define the apparent m o l d volumes for all species e.

CO, aq , 3 Regress the required CO:-, HCO; coefficients based upon simultaneously solving a full electrolyte model with the density equation imbedded. In order to handle a broad spectrum of temperatures, fits should be done across several isotherms and then, can ultimately, the fit coefficients e.

C and I in equation 8. Illustrative Example Fortunately, there is an appreciable body of good density data available on a broad spectrum of HZO-salt binary systems. Furthermore, the availability of high quality density measurements in a number of ternary and quarternary systems means that the mixing rules can be adequately tested.

The references given at the end of this chapter include a number of important sources for these data. Let us now consider each of these in more detail. For purposes of this development, we will take, for aqueous species, the pure component heat of formation at 25OC and infinite dilution as the basis.

Electrolyte solutions, a s we have seen. Thus, in order to compute we will need formulations for both molecular and ionic species. K T Molecular Species For molecular species e. D , Ev,i To. Equation 8. There is, however, an underlying assumption made.

The relationship derived above assumes equilibrium between liquid and vapor, or. In a subcooled liquid the enthalpy predicted by equation 8. Inasmuch a s pressure effects on liquids are often minimal, except at quite elevated pressures above atmospheres , this factor can usually be ignored. Applying a technique known as the correspondence principal. Reviews User-contributed reviews Add a review and share your thoughts with other readers.

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Similar Items. Online version: Handbook of aqueous electrolyte thermodynamics. Machine derived contents note: I. Thermodynamics Of Solutions. Basic Definitions and Concepts. Necessary Conditions. Equilibrium Constants. Criss and Cobble Parameters.

Values for Guggenheim? Values for Uni-univalent Electrolytes. Bromley Interaction Parameters. Pitzer Parameter Derivatives. Values for Pitzer? Worked Examples. Parameters for Beutier and Renon? United States: N. Copy to clipboard. United States. Other availability. Please see Document Availability for additional information on obtaining the full-text document.

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