This book chapter presents an undergraduate-level overview of intermolecular interactions in binary liquid mixtures using dielectric, thermophysical, and ultrasonic approaches. It explains how measurable properties such as density, viscosity, dielectric constant, refractive index, and ultrasonic velocity vary with composition and temperature, and how these variations reflect molecular interactions. Special emphasis is placed on alcohol-containing mixtures due to the role of hydrogen bonding. The concept of excess properties is introduced to distinguish ideal and non-ideal behavior. By correlating macroscopic measurements with microscopic interactions, the chapter highlights the educational value and practical relevance of liquid mixture studies in physics and physical chemistry.