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…

Indicates that the true red color of calcium can be obtained (using the procedure described by Sorm and Logowski) if the calcium ion solution is mixed with an equal volume of saturated ammonium bromide solution. Suggestions for flame tests of other elements are also noted. (JN)

Uses the protactinium (Pa-234m) generator to illustrate the production of isotopes of short half-life for medical analysis. The principle of nuclide generators and suggested experiments (with procedures and typical results) are discussed. (JN)

"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)

Describes experiments in which students determine the ground state ionization constant (GSIC) by analyzing the absorption spectra of 2-naphthol in acidic, basic, and buffered solutions. Information on the ground and excited state ionization constants and on the kinetics of the excited state deprotonation-protonation reaction is included. (JN)

Background information, procedures used, and typical results obtained are provided for an experiment (based on the potassium bromide pressed-pellet method) involving the infrared spectroscopy of deuterated compounds. Deuteration refers to deuterium-hydrogen exchange at active hydrogen sites in the molecule. (JN)

Background information is provided on the natural products found in marine organisms in general and the brown algae in particular. Also provided are the procedures needed to isolate D-mannitol (a primary metabolite) and cholesterol from brown algae. (JN)

Shows that nitric acid can be used as a rapid, versatile, and economical oxidant for selected organic substances. The experiments (with background information, procedures, and results provided) require one three-hour laboratory period but could serve as open-ended projects since substrates not described could be oxidized. (JN)

The goal of many colleges is to make the organic chemistry laboratory completely flameless by using electric heating equipment. Benefits of eliminating the Bunsen burner, electrical heating equipment and accessories, hazards remaining in flameless laboratories, and design standards related to laboratory liability are the major topic areas…

Recommends the Linnett structure IV (as in VIII for molecular oxygen) for future use when a valence-bond structure for a Pauling 3-electron bond is required. Examples are provided to illustrate why this recommendation is made. (JN)

Outlines rules for a group electronegativity method. Also provides examples of this method and examples of other group electronegativities derived by both experimental and computational methods. (JN)

Presents a parallel treatment of the same phenomena by two approaches (steady-state approximation and approximate solution of the appropriate diffusion equation) to clarify the physical meaning of the important radiation boundary condition in the diffusional derivation. (JN)

Four cases which illustrate statistical factors in complexation reactions (where two of the reactants are monodentate ligands) are presented. Included are tables showing statistical factors for the reactions of: (1) square-planar complexes; (2) tetrahedral complexes; and (3) octahedral complexes. (JN)

Describes a chemistry program in which experiments are performed for students in grades one to three. The experiments use only materials and apparatus found in the average home so they can be reported by teachers or parents. Students become involved in the program by asking questions and making predictions. (JN)

Proposes a simple solution to the problem of expressing graphically absolute configuration, racemic character, and relative configuration in molecules. As demonstrated by several examples, the proposed convention brings added clarity and simplicity to structural drawings and renders graphic displays of chiral molecules as explicit and information…