Thermodynamic Functions for Solubility of 1‑Hydroxybenzotriazole in Sixteen Solvents at Temperatures from (278.15 to 313.15) K and Mixing Property of Mixtures
journal contributionposted on 16.06.2017, 12:03 by Jiao Chen, Gaoquan Chen, Chao Cheng, Yang Cong, Cunbin Du, Hongkun Zhao
Solubility of 1-hydroxybenzotriazole in 16 neat solvents including methanol, ethanol, n-propanol, isopropanol, acetone, butanone, isoamyl alcohol, n-hexanol, n-heptanol, isooctyl alcohol, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), ethyl acetate, acetonitrile, 1,4-dioxane, and toluene was measured using the method of isothermal saturation over a temperature range from (278.15 to 313.15) K under atmospheric pressure (101.1 kPa). The mole fraction solubility of 1-hydroxybenzotriazole in the selected solvents increased with an increase of temperature. They followed the order from high to low in studied neat solvents: DMF > DMSO > ethanol > n-propanol > isopropanol > methanol > butanone > acetone >1,4-dioxane > n-heptanol > n-hexanol > isoamyl alcohol > isooctyl alcohol > ethyl acetate > acetonitrile > toluene. The obtained solubility data of 1-hydroxybenzotriazole in the studied solvents were correlated with the λh equation, modified Apelblat equation, and NRTL and Wilson models. The largest value of root-mean-square deviation was 7.65 × 10–4, and relative average deviation, 4.21%. The values of root-mean-square deviation obtained with the modified Apelblat equation were smaller than those with the other equations for a given solvent. By and large, the four thermodynamic models all provided acceptable results for 1-hydroxybenzotriazole in the studied solvents. Moreover, the apparent dissolution enthalpy and the mixing enthalpy, mixing Gibbs energy, mixing entropy, reduced excess enthalpy, and activity coefficient at infinitesimal concentration were derived. The obtained solubility and thermodynamic studies could provide the fundamental data for optimizing the reaction and purification procedure of 1-hydroxybenzotriazole.