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

In this paper, we chose gravimetric analysis to measure the solubility of 4-biphenylcarboxylic acid in nine pure and binary mixed organic solvents from T = 293.15 to 328.15 K. It is demonstrated that with the increase of temperature, the solubility of 4-biphenylcarboxylic acid in each of the solvents increases. Meanwhile, the experimental data are fitted with five classical models: Apelblat, van't Hoff, λh, nonrandom two-liquid (NRTL), and UNIQUAC. The maximum relative average deviations in pure solvents and binary mixed solvents are 0.935 and 1.563%. The fitted result meets the requirements. In addition, this paper also studies the thermodynamic parameters of 4-biphenylcarboxylic acid in the dissolution process and calculates the mixing Gibbs free energy, mixing enthalpy, and mixing entropy during the dissolution process. All of the mixing Gibbs free energy values are less than 0, which shows that the dissolution process is spontaneous.