The color of a solution of thionine turns from purple to colorless within a few seconds when exposed to bright light. The purple color is restored when the light source is removed. By adding various reactants to this complex, redox equilibrium, the rates at which the color changes occur can be studied.
This demonstration illustrates the vast amount of energy which is available from the oxidation of carbohydrates, such as sugar. An excess of oxygen, generated by the decomposition of sodium chlorate, will react with a gummy bear, releasing a large amount of energy quickly and dramatically.
In this experiment, the student will determine the solubility of a variety of solutes in several solvents. The observed solubility will be related to the structure and intermolecular forces of both the solute and solvent. On the basis of these tests, they will then devise and carry out an experimental method for the determination of the percent oil in peanuts.
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Woodrow Wilson Leadership Program in Chemistry
The Woodrow Wilson National Fellowship Foundation
CN 5281, Princeton NJ 08543-5281