Determination, Correlation, and Thermodynamic Analysis of the Solid–Liquid Phase Equilibrium of 1,4-Dicyanobenzene in Pure Solvents at Various Temperatures

Abstract

The solubility of 1,4-dicyanobenzene (DCB) in 17 neat solvents, that is, methanol, ethanol, n-propanol, isopropanol, acetone, ethyl acetate, ethyl formate, methyl acetate, cyclohexanone, cyclopentanone, tetrahydrofuran, 2-butanone, acetonitrile, chloroform, 2-pentanone, dichloromethane, and diethyl ether, was measured via a gravimetric method from 272.95 to 324.15 K under ambient pressure. Within the experimental temperature range, the mole fraction solubility of DCB increased with the rising temperature in all selected solvents, and the order of magnitude is cyclopentanone > dichloromethane > cyclohexanone ≈ tetrahydrofuran > chloroform > (acetone, 2-butanone) > 2-pentanone ≈ methyl acetate > ethyl formate > ethyl acetate > acetonitrile > diethyl ether > methanol > ethanol > n-propanol > isopropanol. The solubility of DCB in ketones was much higher than that in ethers and alcohols. The Wilson model, nonrandom two-liquid model, Apelblat equation, and λh equation were employed to mathematically express the solid–liquid phase equilibrium data of DCB. The maximum values of the root-mean-square and relative average deviations were 9.83 × 10–5 and 5.21 × 10–3, respectively, which indicated that good correlation was recorded between the experimental and calculated data. The dissolution enthalpy, entropy, and Gibbs free energy were calculated on the basis of thermodynamic relations and the Wilson model, which revealed that the dissolution of DCB was a spontaneous and endothermic process.

Experimental Investigation of Binary (Solid + Liquid) Equilibrium and Dissolution Property Analysis for Acetoacetanilide in 16 Organic Solvents at Temperatures from 272.25 to 324.15 K

“…A mercury barometer, which was provided by Shanghai Yun Meteorological Instrument Co., Ltd., was used to measure the atmospheric pressure. The experimental procedure and process were similar to our previous work. − …”

Measurement and Correlation of the Solubility of 4-Biphenylcarboxylic Acid in Nine Pure and Binary Mixed Organic Solvents from T = 293.15 to 328.15 K

“…To determine the melting point T m and melting enthalpy Δ fus H of 4-biphenylcarboxylic acid, the DSC technique was used. − In this process, the instrument system was set from room temperature to 250 °C at a heating rate of 10 K·min –1 , and the whole process was carried out in a nitrogen environment. The flow rate of nitrogen was 10 mL·min –1 .…”

“…1−3 This work summarizes the solubility of 4-biphenylcarboxylic acid in nine pure solvents and methanol−n-butanol binary mixed solvents when the temperature varies from 293. 15 328.15 K under normal pressure, and it is fitted with five models: Apelblat, van't Hoff, λh, NRTL, and UNIQUAC. It can verify the accuracy of the experiment by calculating the relative deviation and the relative average deviation.…”