Study of Thermodynamic and Acoustic Properties of Niacin in Aqueous Hexylene Glycol and Propylene Glycol at Different Temperatures

The densities and speed of sound for liquid mixtures containing vitamin B-3 (niacin) at 0.01, 0.03, and 0.05 mol.kg(-1) concentrations in aqueous propylene glycol and hexylene glycol at the variation of temperatures from 293.15 to 308.15 K have been measured using an Anton Paar DSA 5000 M. From volumetric experimental data, apparent molar volume (V-phi), partial molar volume (V-phi(0)), and partial molar volume of transfer (Delta V-phi(0)) are calculated along with the apparent molar isentropic compression (K-phi,K-s), partial molar isentropic compression (K-phi,s(0)), and partial molar isentropic compression of transfer (Delta K-phi(0)) using experimental acoustic data. The positive volumetric data (i.e., apparent molar volume and partial molar volume) indicates strong solute-solvent interactions inside the mixture. Along with these values, the empirical constants a, b, and c with the pair and triplet coefficients (V-AB, V-ABB, K-AB, K-ABB) are also calculated. calculated.