Setchenow coefficient

The osmotic coefficients calculated from Eq. (9) can be brought into good agreement with solution data up to about 1M for aqueous solutions of alkali (26) and alkaline earth halides, (30) tetraalkyl ammonium halides, T3l) mixed electrolytes, where the Harned coefficients are measured, (32) and electrolyte-non electrolyte mixtures, where Setchenow coefficients are measured. 

Almeida MB, Alvarez AM, de Miguel EM, del Hoyo ES (1983) Setchenow coefficients for naphtols by distribution method. Can J Chem 61 244-248 Amirtharajah A, Raveendran P (1993) Detachment of colloids from sediments and sand grains. Coll Surfaces A, 73 211-227... 

In addition, the high concentrations of ions in solutions of high ionic strength such as sea salt particles (especially near their deliquescence point) can alter gas solubility. In this case, the Henry s law constants must be modified using Setchenow coefficients to take this effect into account (e.g., Kolb et al., 1997). 

De Bruyn, W. J., E. Swartz, J. H. Hu, J. A. Shorter, P. Davidovits, D. R. Worsnop, M. S. Zahniser, and C. E. Kolb, Henry s Law Solubilities and Setchenow Coefficients for Biogenic Reduced Sulfur Species Obtained from Gas-Liquid Uptake Measurements, . /. Geophys. Res., WO, 7245-725 f (f995). 

Krishnan, C.V. and Friedman, H.L. Model calcnlations for Setchenow coefficients. 

Figure 4. Setchenow coefficients calculated from Table 2 as a function of T. Only He reaches a minimum in the experimental range, limiting the ability of this data set to be extrapolated to higher temperatures.

Although the work of Smith and Kennedy only investigates the effect of NaCl on noble gas solubility, they note that the contribution by individual ions should be additive and in dilute brines it should be possible to estimate the salt effect of multi-electrolyte solutions. While no data exists for Mg and Ca ions, data for KI solutions show that kAr is independent of the electrolyte species (Ben-Naim and Egel-Thal 1965), suggesting that an NaCl equivalent concentration provides a reasonable value from which to calculate the Setchenow coefficient. This relationship has been used in multi-ion mixtures such as seawater and for more concentrated solutions such as the Dead Sea brines (Weiss 1970 Weiss and Price 1989). 

In the special case that B is an electrolyte, for example, NaCl or BaCl2, and A is a nonelectrolyte such as benzene or oxygen, the coefficient is called a Setchenow or salting-out coefficient. When A is not too soluble and when there is a convenient method of measuring its concentration, then the Setchenow coefficient is the most easily measured excess free energy function of a solution. 

When both and ntB are vanishingly small then = ka, and so it becomes apparent that they measure the same interaction. " Setchenow coefficient data have been collected for aqueous solutions at... 

Setchenow coefficients for hydrocarbons and for volatile solutes In sea water the osmotic coefficient and density of sea water as a function of temperature and salinity. Thermodynamic solubility products of minerals In brines the activity coefficient of carbon dioxide In sea water speclatlon calculations on copper, zinc, cadmium, and lead In sea water excess Gibbs energies of mixing of electrolyte solutions at 25 C and pairwise and triplet Interaction terms for electrolyte solutions in terms of various models. 

Activity coefficients for uncharged, molecular species generally obey the empirical Setchenow equation up to high ionic strengths (cf, Lewis and Randall 1961 Miller and Schreiber 1982). Such species include dissolved gases, weak acids, and molecular organic species. The Setchenow equation is... 

Ohtaki H, Radnai T (1993) Structure and dynamics of hydrated ions. Chem Rev 93 1157-1204 Parfenyuk VI (2002) Surface potential at the gas-aqueous solution interface. Coll J 64 588-595 Pawilkowski EM, Prausnitz JM (1983) Estimation of Setchenow constants for nonpolar gases in common salts at moderate temperatures. Ind Eng Chem Fund 22 86-90 Pitzer KS (1979) Theory ion interaction approach. In Pytkovicz RM (ed) Activity coefficients in electrolyte solutions, Vol. 1. CRC Press, Boca Raton, (Chap. 7)... 

Plyasunov et al. (1988) used a combination of the Debye-Hiickel and Setchenow approximations together with literature data for the activity coefficients of NaOH solutions to determine the dissociation constant of NaOH(aq) from 0 to 350 °C. The combination of the approximations was used such that the calculated activity coefficients best matched the literature values whilst obtaining values for the dissociation constant at each temperature. In general, the values of the dissociation constant (obtained from the reverse of reaction (2.7) (M = Na, p=l, q=i)) were found to increase with increasing temperature they also increased slightly below 50 °C. However, when combined with the dissociation constant of water (i.e. for reaction (2.5)), the stability constants increase with increasing temperature across the whole temperature range (see Table 6.5). The data obtained by Plyasunov et al. (1988) are more positive than those of other studies at low temperature but become more consistent with other data at, and above, a temperature of 150 °C. There is no apparent reason to reject any of the data, and so all are retained in the present review. 

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