Solubility of 5-Amino Salicylic Acid in Different Solvents at Various Temperatures

Abstract

The solubility data of 5-amino salicylic acid in methanol, ethanol, carbon tetrachloride, and tetrahydrofuran (THF) at various temperatures were measured by gravimetrical method from (293.15 to 313.15) K under atmospheric pressure, and the solubility data were correlated as a function of temperature. The order of solubility is THF > carbon tetrachloride > ethanol > methanol. Further, some thermodynamic parameters such as enthalpy, Gibb’s energy, and entropy have also been evaluated for the dissolution process. It is observed that enthalpy and entropy are positive, whereas the Gibb’s energy of activation is negative for all of the four solvents. The negative Gibb’s energy suggests the spontaneous nature of dissolution process, whereas positive enthalpy indicates endothermic dissolution of compounds. The positive entropy is due to favorable dissolution in the studied solvents.

Solubilities of Adipic Acid, Glutaric Acid, and Succinic Acid in Dimethyl Glutarate + Methanol Mixtures: Experimental Measurement and Thermodynamic Modeling

“…The thermodynamic functions of solution such as the Gibbs free energy and dissolution enthalpy were beneficial to exploring the dissolution process. Therefore, they were calculated from the measured solubility data by the method of van’t Hoff, which was expressed as eq . − In eq , R is equal to 8.314 J·mol –1 ·K –1 , and the mean harmonic temperature T hm is defined in eq : − where n represents the number of temperatures considered. The corresponding T hm values are displayed in Table .…”

Solubility determination and thermodynamic models for dehydroepiandrosterone acetate in mixed solvents of (ethyl acetate + methanol), (ethyl acetate + ethanol) and (ethyl acetate + isopropanol)

“…The standard dissolution enthalpy ðDH o sol Þ of DHEA-acetate dissolved in solvent mixtures may be computed using a modified version of the famous van't Hoff analysis [18,19].…”

Concentration and Temperature Dependences of 2-Chloro-3-(trifluoromethyl)pyridine Solubilities in (DMF + Tetrahydrofuran) and (DMF + Isopropanol) Mixtures

“…The relative deviation (RD) and the root-meansquare deviation (RMSD) [12,13] were used to evaluate different models, and the expression of the two equations are as follows:…”

“…The T mean is the mean value of the experimental temperatures. (13) At the same time, the effect of and to Gibbs energy was calculated, and the following two equations were employed to express the difference between them [13]:…”