Ultrasonic Speeds, Excess Volumetric Parameters, and Intermolecular Interactions of Binary Liquid Systems of Octanol with Aliphatic Amines

International Journal of Chemistry | Vol. 17, No. 8, August 2026 | pp. 57–64

DOI: 10.46882/2026/IJC/000214

Article Type: Original Research Paper

Title: Ultrasonic Speeds, Excess Volumetric Parameters, and Intermolecular Interactions of Binary Liquid Systems of Octanol with Aliphatic Amines

Names of Authors: E. C. Chiemeka¹, A. M. H. Al-Ghamdi²*

Authors’ Affiliations:
¹Department of Chemistry, Federal University of Technology, Owerri, Nigeria.
²Department of Chemistry, University of Khartoum, Khartoum, Sudan.

Abstract: Experimental determination of ultrasonic velocities and fluid densities across varied temperature states yields critical baseline data needed to map hydrogen bond associations and molecular packing dynamics in multi-component chemical systems. This paper presents the measurement of ultrasonic velocity (u), density (rho), and dynamic viscosity (eta) for binary liquid mixtures of n-octanol with diethylamine, triethylamine, and cyclohexylamine across the entire composition matrix at temperatures of 298.15 K, 308.15 K, and 318.15 K under atmospheric pressure. From these raw data metrics, excess molar volumes (V^E) and excess isentropic compressibilities (kappa_s^E) were calculated. The calculated excess datasets were successfully fitted to the Redlich-Kister polynomial expression to compute the binary interaction coefficients and standard deviations. All investigated binary mixtures exhibited significant negative excess molar volumes (V^E) and negative excess isentropic compressibilities (kappa_s^E) across all composition bounds. These strong negative deviations reveal dense interstitial molecular packing and strong intermolecular hydrogen bond formation between the hydroxyl protons of n-octanol and the amine nitrogen centers, which decrease in intensity as thermal motion breaks the dipole networks.

Keywords: Ultrasonic velocity; Excess molar volume; Isentropic compressibility; Aliphatic amines; Redlich-Kister equation; Hydrogen bonding

Manuscript Timeline: Received: February 05, 2025; Revised: March 12, 2025; Accepted: April 08, 2025; Published: August 03, 2026.

Citation: Chiemeka, E. C., & Al-Ghamdi, A. M. H. (2026). Ultrasonic Speeds, Excess Volumetric Parameters, and Intermolecular Interactions of Binary Liquid Systems of Octanol with Aliphatic Amines. International Journal of Chemistry, 17(8), 57–64.

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