A Discovery Approach to Three Organic Laboratory Techniques: Extraction, Recrystallization, and Distillation

ÊA simple approach for THE DETERMINATION AND CHARACTERIZATION OF TERNARY PHASE DIAGRAMS of aqueous two-phase systems composed of water, poly(ethylene) glycol and sodium carbonate

“…Once a TL is determined, the calculation of the tie-line length (TLL) is a straightforward procedure, using the equation shown below: (9) As mentioned before, several tie-lines are obtained for each system. Also, the compositions of the two phases become equal at the critical point.…”

“…The determination of ternary phase diagrams of ATPS composed of water, sodium carbonate and PEG of different molecular weights is proposed. Several laboratory experiments aimed at teaching liquid-liquid extraction have been reported, [7][8][9][10][11][12][13][14] yet few involve the determination of the ternary liquid-liquid phase diagrams. [15][16][17][18][19] Since ATPS are here proposed, this work also provides the opportunity to discuss the environmental advantages associated to water-rich systems.…”

The Problem with Organic Chemistry Labs

“…This change will provide a student experience that involves thought as well as basic lab skills. Fortunately, a number of useful examples of inquiry-based experiments and projects have been published recently (4)(5)(6)(7)(8)(9)(10).…”

Upper Secondary School and University Level Students’ Perceptions of Extractions in Context: Experiences from a Simple Laboratory Experiment

“…Our goal in designing thereof was to make it easy for students to make clear observations and limit the experimental complexity associated with using unfamiliar laboratory glassware, such as separatory funnels. (Horowitz 2003, Loyo-Rosales et al 2006 We made this choice as student's focus on fundamental chemistry is easily shifted toward the mechanical task of building complex pieces of apparatus. While such mechanical skills are important in science, laboratory experiment's practical complexity can misguide students from the deeper fundamental phenomenon.…”