Nonlinear ultrasound propagation in formamide + 2-methoxyethanol/2-ethoxyethanol solvent systems at temperatures ranging from 303.15 to 323.15 K

Nonlinear ultrasound propagation of formamide with 2-methoxyethanol and 2-ethoxyethanol systems are examined over the entire miscibility range and five different temperatures (303.15 K ≤ T ≤ 323.15 K) using Hartmann, Ballou, Lu, Tong Dong, Beyer and Beyer-Tong Dong methods. The nonlinearity parameter, B/A values are compared using the aforementioned methods in both the binary systems. The isobaric temperature coefficient ∂u/∂TP\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left( {{{\partial u} \mathord{\left/ {\vphantom {{\partial u} {\partial T}}} \right. \kern-\nulldelimiterspace} {\partial T}}} \right)_{P}$$\end{document} and isothermal pressure coefficient of the ultrasound velocity ∂u/∂PT\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\left( {{{\partial u} \mathord{\left/ {\vphantom {{\partial u} {\partial P}}} \right. \kern-\nulldelimiterspace} {\partial P}}} \right)_{T}$$\end{document} are also calculated. An interconnection between nonlinear ultrasound parameter and the molecular properties e.g. internal pressure, cohesive energy density etc. is also discussed. The excess non-linearity parameter B/AE plays a key role in determining the extent of intermolecular interactions in binary liquid mixtures. Hence, nonlinear ultrasonic propagation helps in studying the static and dynamic molecular properties of the solvent systems.