Volumetric and Viscometric Approach to Understand Molecular Interactions of Tetra-n-propylammonium Bromide in Water and Aqueous Mixtures of 1,3-Dioxolane and Tetrahydrofuran at Different Temperatures

• Published in: Russian Journal of Physical Chemistry A 2022-12, Vol.96 (14), p.3135-3148
• Main Authors: Nanda, Braja B., Talukdar, Malabika
• Format: Article
• Language: English
• Subjects: Ammonium bromides; Chemistry; Chemistry and Materials Science; Density; Mathematical analysis; Molar volume; Molecular interactions; Parameters; Physical Chemistry; Physical Chemistry of Solutions; Solvents; Tetrahydrofuran; Viscosity; Viscous flow
• ISSN: 0036-0244; 1531-863X
• DOI: 10.1134/S0036024423020036

The present investigation is made on a surface-active organic ammonium halide, tetra- n -propyl ammonium bromide dissolved in water and (water + 1,3-dioxolane and tetrahydrofuran). Volumetric and viscometric parameters are computed from experimentally measured density and viscosity data. Experimental temperatures range from 298.15–313.15 K with 5 K intervals. Apparent molar volume, , and partial molar volumes, thus calculated from density ( values are used to predict ion–ion and ion–solvent interactions. Magnitudes of partial molar expansibility, and Hepler’s constant (∂ 2 /∂ T 2 ) p are indicative of the structure making/ breaking behavior of solute and caging effect of solvent. Viscosity coefficients are interpreted in terms of ion–ion and ion–solvent interactions. Positive values of Helper’s constant (∂ 2 /∂ T 2 ) p and the negative values of ∂ /∂ T establish tetra- n -propylammonium bromide (TPAB) as a structure maker. Thermodynamic parameters like , , and involved in the viscous flow of solution suggest that attending a higher energy transition state is necessary in order to resume the viscous flow.