Solubility of gallic acid in liquid mixtures of (ethanol+water) from (293.15 to 318.15)K

• Published in: The Journal of chemical thermodynamics 2012-12, Vol.55, p.75-78
• Main Authors: Noubigh, Adel, jeribi, Chokri, Mgaidi, Arbi, Abderrabba, Manef
• Format: Article
• Language: English
• Subjects: Chemical thermodynamics; Chemistry; Exact sciences and technology; Gallic acid; General and physical chemistry; General. Theory; Mixed solvents; Solubility; Temperature dependence; Thermodynamic properties
• ISSN: 0021-9614; 1096-3626
• DOI: 10.1016/j.jct.2012.06.022

Solubility of gallic acid vs the mole fraction of ethanol (0.0 to 1) on a solute-free basis in ethanol+water at different temperatures/K. □, 293.15; Δ, 298.15; ◊, 303.15; line calculated by equation (6). [Display omitted] ► Solubilities of gallic acid in binary mixtures were determined over the temperatures range (293.15 to 318.15)K. ► The gallic acid solubility in mixed solvents presents a maximum-solubility effect. ► Two empirical equations were proposed to correlate the solubility Data. ► The thermodynamic properties were determined. The solubility of gallic acid in (water + ethanol) binary solvents was determined from (293.15 to 318.15)K at atmospheric pressure using a thermostatted reactor and UV/vis spectrophotometer analysis. The effects of binary solvents composition and temperature on the solubility were discussed. It was found that gallic acid solubility in (water+ethanol) mixed solvents presents a maximum-solubility effect. Two empirical equations were proposed to correlate the solubility data. The calculated solubilities show good agreement with the experimental data within the studied temperature range. Using the experimentally measured solubilities, the thermodynamic properties of dissolution of the gallic acid such as Gibbs energy (ΔsolG°), molar enthalpy of dissolution (ΔsolH°), and molar entropy of dissolution (ΔsolS°) were calculated.