ISSN:
1572-8927
Keywords:
Isosaccharinic acid
;
solubility product
;
aqueous complexes
;
Ca complexes
;
thermodynamic data
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract The solubility of calcium isosaccharinate Ca(ISA)2(c) was determined at 23°C as a function of pH (1–14) and calcium ion molality (0.03–0.52). The similarity of solubility from the over- and undersaturation directions for different equilibration periods indicated that equilibrium in these solutions was reached rapidly (〈 7 days) and that these data can be used to develop thermodynamic equilibrium constants. The solubility data were interpreted using the Pitzer ion–interaction model. The logarithms of the thermodynamic equilibrium constants determined from these data were 1.30 for the dominant reaction at pH 〈 4.5 [Ca(ISA)2(c) + 2H+ ⇌ Ca2+ + 2HISA(aq)], and −2.22 for the dominant reaction at 4.5 [Ca(ISA)2(c)+ ⇌ Ca(ISA)2(aq)]. In addition, the logarithm of the dissociation constant of HISA [HISA(aq) ⇌ ISA- + H+] was calculated to be −4.46.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022610001043
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