This post describes a simple way to generate blue, green, orange, and yellow copper complexes, and to use these complexes to introduce students to the effect of temperature on chemical equilibria. The protcol avoids the use of caustic agents, allowing the experiments to be conducted by students as a laboratory-based investigation.
Le Chatelier's Principle
Solutions of copper (II) dissolved in acetone are easy to prepare, and can display orange, yellow, green, and blue color depending upon conditions. Such solutions allow for a variety of demonstrations and experiments that illustrate principles of chemical equilibrium.
Is it time for us as chemistry teachers to move beyond the Le Châtelier Principle as justification for why disturbances to equilibrium systems cause particular “shifts”? The author shares his new approach to teach equilibrium and provide his students with a more rigorous understanding of the concept.
Teachers are accustomed to implementing new learning standards developed by state or national leaders. My state, Georgia, chose not to adopt the newest national standards. State leaders wrote the “Georgia Standards of Excellence” instead. Full implementation of the GSE begins in the 2017-2018 school year.