Reviews research on the purpose and effectiveness of laboratory activities. Discusses epistemology, problem solving, cooperative learning, student involvement, assessment, and teachers as researchers. (YP)

Chromium(VI) compounds are classified as oxidizers and must be specially packaged and transported for disposal while Cr(III) compounds are considered nonoxidizers. A process which reduces Cr(VI) to Cr(III) by adding sodium metabisulfite followed by neutralization with magnesium hydroxide is explored. (MVL)

Shows that the mutual repulsion that enables a superconductor to levitate a magnet and a magnet to levitate a superconductor can be combined into a single demonstration. Uses an overhead projector, two pellets of "1-2-3" superconductor, Nd-Fe-B magnets, liquid nitrogen, and paraffin. Offers superconductor preparation, hazards, and disposal…

Presents the construction aspects of a simple but reliable colorimeter made from locally available components. Notes the absorption range to be 400-750-nm. Lists seven experiments done on the instrument. (MVL)

Described is a laboratory procedure for teaching seed stratification. Materials, methods, results, and applicability of the experiment are explained. Diagrams showing the percent of total germination as a function of stratification time and the germination rate of stratified seeds are included. (RT)

Presents an overview of coatings along with paint preparation labs. Provides students with information about and methods for preparing a product that is an integral part of daily life. Gives methodology which can be used to prepare oil based and water based paints. (MVL)

Reports that although excitation at 337nm is less than optimal, detection limits in the range 1-100pg/ml were found. Provides a calibration curve and results for seven organic compounds. (MVL)

Describes a science presentation which promotes various ways to improve laboratory safety. Recommendations for storing chemicals include: minimize the type and amount of stocked materials, purchase certain chemicals in small quantities, and use plastic embedments. Cites several books for reference. (RT)

Describes a photochemistry experiment designed to introduce photochemical techniques and experience free radical chemistry. Selects Nuclear Magnetic Resonance spectroscopy for the analysis. This activity is suggested for use in an upper level undergraduate organic course. (MVL)

Presents a high school chemistry lab experiment using tin (II) chloride to explore the concepts of hydrolysis, Le Chatelier's principle, and electrolysis. Presents methodology and the chemistry involved. Offers questions for the students. (MVL)

Describes some reactions for the identification and application of cyanuric acid. Suggests students may find this applied chemistry interesting because of the use of cyanuric acid in swimming pools and diesel engines. Lists three tests for cyanate ion and two tests for cyanuric acid. (MVL)

Described is a project where students gain experience in handling large volumes of hazardous materials, process start up and shut down, equipment failures, operational variations, scaling up, equipment cleaning, and run-time scheduling while working in a modern pilot plant. Included are the system design, experimental procedures, and results. (KR)

Describes the generation and use of experimental data in teaching economics. Includes a double oral auction experiment and a monopoly pricing experiment. Concludes that such experiments allow the instructor to see what the students have learned, how they reason, and what parts of the material have proved difficult. (DK)

A simple experimental arrangement that makes it possible to simultaneously observe and compare on a screen the two interference patterns produced by reflected and transmitted light from incident white light impinging on a soap film directly is described. Procedures and illustrated effects are discussed. (CW)

Two experiments which can be used to illustrate light diffraction using compact disks are detailed. Included are procedures, computations, and probable results. (CW)