Designing a Green Experiment for the Physical Chemistry Lab-Simple Two-component Solid-liquid Phase Equilibrium System

Phase equilibrium systems are important topics in physical chemistry. As the practical training of phases contributes to a deeper understanding of this part of science, planning an agenda with a green chemistry approach and attention to human health is essential. In this study, a simple solid-liquid phase equilibrium system, palmitic acid - oleic acid, replaced the naphthalene - benzene or naphthalene - toluene system. This system not only can this system meet the educational goals of this department, but it also has the capability to recycle consumables and use waste as raw materials in other training laboratories. It is also affordable for an undergraduate training lab. From this simple experiment, the melting point of palmitic acid was 64° C and the melting enthalpy of this material was 40.69 kJ / mol. Compared to the actual values, due to the simple tools and the purity of the material used, it has an acceptable error percentage. It is noteworthy that the same uncertainty also is observed in the results of naphthalene-toluene system.