Described is a modified Fehling test and a modified corrected Benedict test. (RH)

Described is a simple demonstration that provides a way to determine if a given sample contains even a small fraction of superconducting material. The repulsion of the powder from a magnetic field is indicative of superconductivity. (RH)

This is part two in a series on classroom demonstrations of polymer principles. Described is how large molecules can be assembled from subunits (the process of polymerization). Examples chosen include both linear and branched or cross-linked molecules. (RH)

The author discusses emerging trends in popular education, including various grassroots experiments and projects. He describes popular education not as a component of modernization programs but as a movement that begins with the people. (CH)

Experiments involving the coupling of alkyl and aryl halides in the presence of lithium metal and ultrasound are described. The experiments illustrate classical Wurtz and Fittig reactions in addition to being a convenient application of organic sonochemistry. (JN)

The semipermeability of biological membranes is simply and directly illustrated in an experiment which uses ovolecithin liposomes as convenient models for biological membranes. Background information and procedures used are provided. (JN)

Discusses features of experiments (conducted during 1980-81 in the University of Edinburgh's third-year chemical engineering laboratory) which might make them attractive for wider use. Experiments focus on convective mass and heat transfer, diffusion, heat transfer to a jet, and adiabatic batch reactors. (JN)

A three-period experiment was developed to help students visualize asymmetric distribution of proteins within membranes. It includes: (1) isolating erythrocyte membranes; (2) differential labeling of intact erythrocytes and isolated erythrocyte membranes with an impermeable fluorescent dye; and (3) separating proteins by polyacrylamide gel…

"Colloid titration" is a volumetric method for determining charged polyelectrolytes in aqueous solutions. The principle of colloid titration, reagents used in the procedure, methods of endpoint detection, preparation of reagent solutions, general procedure used, results obtained, and pH profile of colloid titration are considered. (JN)

Background information and experimental procedures are provided for an experiment in which three samples of saccharin (a nickel plating solution, a dilute cola drink, and a more concentrated cola drink) are analyzed and the data interpreted using five methods. Precision and accuracy are evaluated and the best method is selected. (JN)

Describes an experiment (taking approximately five hours) which illustrates the binding of a small molecule to a protein. By using an appropriate fluorescent ligand and a given protein, the fluorescent probe technique is applied to measure the number of bonding sites, and number of site classes, and their association constants. (JN)

Two experiments in which an enzyme is immobilized onto a polymeric support are described. The experiments (which also demonstrate two different polymer preparations) involve: (1) entrapping an enzyme in an acrylamide polymer; and (2) reacting the amino groups on the enzyme's (esterase) lysine residues with an activated polymer. (JN)

Describes a computer program used in an experiment in which the partial molal volumes of sodium chloride solutions are calculated as a function of concentration from densities measured with a pycnometer. The complete program listing (also available from the author on disk) and a sample run are included. (JN)

Provides an overview of obsidian hydration dating for the instructor by presenting: (1) principles of the method; (2) procedures; (3) applications; and (4) limitations. The theory of the method and one or more laboratory exercises can be easily introduced into the undergraduate geology curriculum. (JN)

Describes an experiment to provide students with: (1) an introduction to photochemical techniques and theory; (2) an experience with semimicro techniques; (3) an application of carbon-14 nuclear magnetic resonance; and (4) a laboratory with some qualities of a genuine experiment. These criteria are met in the photooxidation of 9,…