Ternary Diagram: Teaching Ternary Phase Diagrams through Physical Chemistry Laboratory Practicum on Liquid–Liquid Equilibrium

The ternary diagram is an essential graphical tool used to represent the compositional relationships among three components within a system at constant temperature and pressure. This study aims to describe the theoretical foundations, construction methods, and practical interpretations of ternary phase diagrams while evaluating their advantages and limitations in scientific applications. The research method employed was a literature-based analytical review of peer-reviewed journal articles published between 2015 and 2023, focusing on chemical engineering, materials science, and environmental systems. The analysis emphasized the use of quantitative NMR, CALPHAD thermodynamic modeling, and graphical projection techniques to construct accurate ternary phase diagrams. Results from the reviewed literature show that ternary diagrams effectively visualize phase equilibria, compositional trends, and material compatibility, offering a single two-dimensional representation of three-component systems. The diagrams were also shown to support diverse applications such as alloy design, solubility mapping, soil classification, and multivariate statistical analysis. However, the study identified inherent limitations, including restrictions to three components and potential errors arising from data normalization or non-equilibrium conditions. Overall, ternary diagrams remain a fundamental visualization and interpretative tool, combining simplicity and scientific depth in understanding multicomponent systems across various disciplines.