Strategies of Learning Graduate Level Experiments and Its Application for the Removal of Toxic Waste Related To Mutual Solubility of Liquids and Phase Coexistence

This paper describes graduate chemistry practical related to mutual solubility of liquids and phase coexistence. The diversity of the phase transition shows that heating produces mixing and separation. The practical consists of short experiment on the general theme of miscibility of aqueous and organic phases by varying the temperature. The phases were selected as phenol - water and nicotine- water system. The experiment was preceded by the interaction of equal quantities of phenol-water and nicotine-water at room temperature and higher temperature about 80°C. There was a change in miscibility of phases at higher temperature. At about 80°C the phenolwater mixture becomes monophasic while it is heterogeneous at room temperature. The water – phenol phase show limited miscibility below 70°C. While the nicotine -water phases become heterogenous at higher temperature and at room temperature they were monophasic. The temperature at which these phases were merges is known as clearing temperature or cloud temperature. It lies on the liquid-liquid coexistence line. The experiment required careful observations by students at various temperatures ranges from 20°C to 100°C at the step of 20°C and followed by result and discussions. Analysis of the data predicted that students were enjoying by working out the practical and it would be bestowing tremendously beneficial learning experience. The aim of this study was to explore the concept of the phenomenon of phase changes by varying the temperatures and can interpret macroscopic and microscopic properties of the system by relating to the thermodynamic properties. These experiments were beneficial for the isolation and separation of toxic compounds like nicotine and phenol from the waste stream. It is effective and low cost method to save the environment and ecosystem.