Equilibrium solubility, solvent effect, solvation and thermodynamic modeling of 1, 3-dinitropyrazole in solutions of methyl alcohol /ethyl alcohol + water

Abstract

1,3-dinitropyrazole's (DNP) solubility was studied by utilizing the gravimetric method across temperatures ranging 278.15 to 318.15 K and a pressure of 101.2 kPa. In the study, two solvent mixtures were investigated: aqueous methyl alcohol and aqueous ethyl alcohol. Based on the findings, higher temperatures favorably influenced solute dissolution in both solvent systems. To relate the solubility of DNP in two binary solvents mixture, the KAT-LSER model was used. This implies that the polarity of the solvents, as well as the cavity term and hydrogen bonding interactions were pivotal to DNP's solubility. By utilizing the Jouyban-Acree, van't Hoff-Jouyban-Acree, Apelblat-Jouyban-Acree and Ma models, the derived results were compiled. The experimental results prove that the Apelblat-Jouyban-Acree model could give the best correlation results with the experimental data, with the overall relative average deviation values (RAD) of 2.05 %, 2.51 % and the root mean-square deviation (RMSD) of 0.415 × 10⁻⁴, 0.492 × 10⁻⁴ in aqueous methyl alcohol and aqueous ethyl alcohol, respectively. Using the inverse Kirkwood–Buff integrals method, the preferential solvation parameters for the solute DNP determined. The obtained results show that DNP exhibited a preference for solvation in methyl alcohol and ethyl alcohol at all mole fractions of alcohol.