This safe and efficient procedure for the synthesis of N-substituted amides and hydrazides is a modification of the Schotten-Bausmann procedure in which the amine or hydrazide is replaced by the corresponding hydrochloride salt, and the use of alkali is eliminated. (Author/BB)

Describes a laboratory procedure to obtain nuclear magnetic resonance (NMR) values for common organic and inorganic groups. (CP)

A photoelectric on-point detector for Winkler oxygen titrations is described. (MR)

Procedures are provided for a flame emission experiment which covers five areas in a single laboratory exercise. These areas are: (1) the flame emission technique; (2) calibration plots; (3) interferences; (4) indirect flame emission analysis; and (5) techniques of removing interferences. Typical results obtained are discussed. (JN)

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

Described is a teaching method for chemistry that gives college students practice in experimental design. Students are given a problem and required to design a procedure to solve the problem. Problems increase in complexity as the students progress through the courses. (RH)

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)

Clearing is a simple and rapid technique in which 75 percent lactic acid is used to remove pigments and cytoplasmic contents of fresh leaves, enabling microscopic view of various internal leaf layers. Procedures for using the technique (which helps students gain a more thorough understanding of plant anatomy) are given. (DH)

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)

Gives historical background on the discovery of natural radiation and discusses various techniques for using knowledge of radiochemistry in geochronological studies. Indicates that of these radioactive techniques, Potassium-40/Argon-40 dating is used most often. (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)