Thermodynamics of proton dissociations from aqueous l -tartaric acid at temperatures 278.15⩽⩽⩽ (T/K)⩽⩽⩽ 393.15 and at the pressurep= 0.35 MPa: apparent molar volumes and apparent molar heat capacities ofl -tartaric acid and its sodium salts

Apparent and standard partial molar heat capacities and volumes of aqueous tartaric acid and its sodium salts at elevated temperature and pressure

“…The only other reported experimental study of apparent molar volumes and heat capacities of tartaric acid and its salts that covers an extended temperature range is that of Patterson and Woolley [20] which was done after our work was complete. While the experimental values for V / and C p;/ lie within the combined experimental uncertainties, there are significant differences in the extrapolated standard partial molar properties, particularly those for C p as listed in table 7.…”

“…Values for C p;2 (H 2 Tar(aq)), and C p;2 (Na 2 Tar(aq)) were taken from the parameters in table 5 that correspond to equation (11), with uncertainties determined from the 95% confidence limits plus our estimate of possible systematic errors. Values of C p;2 from the isothermal fits and recent values reported by Patterson and Woolley [20] are also listed in table 7 for comparison. The values for V 2 (H 2 Tar(aq)) and V 2 (Na 2 Tar(aq)) in table 8 were taken from the global fit of equations (10) and (13).…”

“…The experimental values of V 2 (H 2 Tar(aq)), V 2 (Na 2 Tar(aq)) and C p;2 (H 2 Tar(aq)) from our measurements at T ¼ 298:15 K were compared with literature values [14][15][16][17][18] in our previous paper [19], and by Patterson and Woolley [20]. Generally, the results for the apparent molar properties agreed to within the combined experimental uncertainties; however, there were some differences in the extrapolations to infinite dilution which are discussed in more detail below.…”

“…The apparent molar volumes and heat capacities of tartaric acid and its salts near 298.15 K have been determined by Apelblat and Manzurola [14,15], Sijpkes et al [16], Høiland and Vikingstad [17,18] and by our laboratory [19]. Very recently, Patterson and Woolley [20] reported measurements at temperatures up to 393.15 K. No studies of the standard partial molar properties of tartaric acid or its salts above 393.15 K have been reported in the literature.…”

“…( ) this work (table 4); ( ) Patterson and Woolley[20]; (---) HKF model;(-) global fits of equations(10) and(14), which are indistinguishable on this scale.…”