Do-It-Yourself Experiments for the Instructional Laboratory

A new design for experiments in the general chemistry laboratory incorporates a "do-it-yourself" component for students. In this design, students perform proven experiments to gain experience with techniques for about two-thirds of a laboratory session and then spend the last part in the do-it-yourself component, applying the techniques to an experiment of their own design. An emphasis on classifying inorganic reactions as acid-base, redox, complexation, and precipitation supports this program. An example is an enthalpy of reaction experiment in which students study an acid-base reaction, a complexation reaction, a precipitation reaction, and a redox reaction. Students perform three of the proven reactions and then do the fourth type with a reaction of their choosing. Other examples of experiments are described. The do-it-yourself component engages students in design and interpretation within a reasonable framework. With this approach, students take chances with new ideas as do working scientists.