Open AccessEstimation of diffusion coefficients of ascorbate-based ions at infinite dilution through electrolytic conductivity measurements
Author(s) -
Allan N. Soriano,
K G R Dollente,
R J D Tabaquero,
Adonis P. Adornado
Publication year - 2018
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/191/1/012028
Subject(s) - dilution , diffusion , chemistry , ascorbic acid , conductivity , molar conductivity , electrolyte , analytical chemistry (journal) , solubility , ion , activity coefficient , molar concentration , nernst equation , thermodynamics , inorganic chemistry , aqueous solution , chromatography , organic chemistry , physics , food science , electrode
Ascorbic acid is a naturally-occurring organic compound that has high water solubility. One significant parameter that can describe the mobility and transport of ascorbic acid and its mineral salts in water systems is the diffusion coefficient. Molar conductivity data were determined from electrolytic conductivity data measured at different concentrations of ascorbate-based ions (dilute region) and temperatures (293.15 to 313.15 K). From these data, the infinite dilution diffusion coefficients of the ascorbic acid and mineral salts in water were estimated using the Nernst-Haskell Equation. The Nernst-Einstein Equation was used to predict the infinite dilution self-diffusion coefficients of the representative ascorbate-based ions ([H + ], [Na + ], and [Ca 2+ ]). For most temperatures and concentrations considered, the Ca 2+ cation had the highest molar conductivity but the [H + ] cation had the highest correlated infinite dilution self-diffusion coefficient of 11.4105 × 10 −9 m 2 /s at 313.15 K. The [Na+] and [Ca 2+ ] cations had values of correlated infinite dilution self-diffusion coefficient of 2.6263 × 10 −9 m 2 /s and 2.4045 × 10 −9 m 2 /s at 313.15 K, respectively. The molar conductivity and diffusion coefficient of the ions at infinite dilution were in the order of [H + ] > [Na + ] > [Ca 2+ ]. It was found that an increase in temperature also increases the diffusion coefficient. This study was able to estimate infinite dilution diffusion coefficient data for ascorbate-based ions. Thus, the results of this study can serve as a basis and reference for future researches to have a better understanding of the fate and transport of ascorbate-based ions in the environment.