Enthalpies of dilution of sodium carbonate and sodium hydrogen carbonate solutions, and the standard enthalpies of ionization of aqueous carbonic acid, at 298.15 K

IUPAC-NIST Solubility Data Series. 95. Alkaline Earth Carbonates in Aqueous Systems. Part 1. Introduction, Be and Mg

“…Because of the difference in accuracy of the measurements, the data of Harned and Davis 50 obtained in an electrochemical cell were given a ten times higher weight than the data of Read 53 obtained with conductivity measurements. When the heat of reaction at 298.15 K was not forced to be 9155 J mol À1 (the value of Berg and Vanderzee 37,38 ), a significantly different value was obtained. Hence, the value was forced to be 9155 J mol À1 using the approach expressed in Eq.…”

“…The CODATA value is based on accurate calorimetric measurements of Berg and Vanderzee. 37,38 The cause of the discrepancy is the fact that both equations derived by Crovetto 32 appear to overestimate k H around 100 C, leading to an overestimated temperature dependence of k H at 25 C. This is probably due to the limited number of data points in this range available to Crovetto. 32 Adding a term in s did not improve the fit.…”

“…Preliminary analysis, as well as simple smoothing of the original K 1 data, indicated that there is a slight inconsistency with the CODATA 35 enthalpy of reaction at 25 C. The latter is based on accurate calorimetric measurements of Berg and Vanderzee. 37,38 For that reason, Eq. (84) was made consistent with the measured enthalpy of reaction of H 1 ¼ 9155 J mol À1 at T 1 ¼ 298.15 K using the approach described below.…”

Thermodynamics of aqueous carbonate solutions including mixtures of sodium carbonate, bicarbonate, and chloride

“…For the enthalpy of these systems we adopt the recent results of Berg and Vanderzee [18]. These authors measured the enthalpy of dilution of sodium carbonate and sodium bicarbonate solutions at 298 K, and corrected their measurements for heat effects arising from equilibria (1).,…”

“…The enthalpies of dilution reported by Berg and Vanderzee [18] could be incorporated into the present analysis through equation (11) in a comprehensive simultaneous treatment of all experimental data.…”