Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

ABSTRACT

The solid-liquid phase equilibrium of 5-phenyltetrazole in thirteen mono-solvents including methanol, ethanol, n-propanol, isopropanol, acetone, 2-butanone, acetonitrile, ethyl acetate, toluene, 1,4-dioxane, cyclohexane, dimethyl sulfoxide (DMSO), N,N-dimethyl formamide (DMF) and liquid mixtures (methanol + ethyl acetate) were obtained experimentally via the isothermal saturation method within the temperatures from (283.15 to 318.15) K under about 101.2 kPa. It was intuitive to notice that the solubility values of 5-phenyltetrazole in studied solvents increased with increasing temperature. The descending order of the solubility data in different mono-solvents was as follows: DMSO greater than DMF greater than acetone greater than methanol greater than (ethanol, 2-butanone) greater than isopropanol greater than n-propanol greater than 1,4-dioxane greater than ethyl acetate greater than acetonitrile greater than toluene greater than cyclohexane. For the binary solvent mixtures of (methanol + ethyl acetate) with given initial compositions, the maximum solubility was observed in neat methanol. The solubility data in mono-solvents were correlated and calculated by using the modified Apelblat equation and the Buchowski-Ksia^2 _zczak kh equation; and in the binary solvent mixtures, by three cosolvency models. The largest values of RAD and RMSD were 1.25% and 4.83 10 4, respectively. The apparent dissolution enthalpy was positive, illustrating that the dissolution process of 5-phenyltetrazole was endothermic. Finally, the preferential solvation parameters (dx1,3) of 5-phenyltetrazole in (methanol + ethyl acetate) mixtures at (293.15 313.15) K were derived by using the inverse Kirkwood Buff integrals method. The dx1,3 values were positive in methanol-rich compositions and negative in the other regions.