Hydantoins are a drug family lying within the broadly related ureide structural frame which encompasses many of the anticonvulsant drugs used in treatment of various types of epilepsy. Background information and experimental procedures are provided for the synthesis of the hydantoin 5,5-diphenylhydantoin. (JN)

Describes a simple, inexpensive electronic circuit used as a small analog computer in an experimental approach to the study of oscillations. Includes circuit diagram and an example of the method using steps followed by students studying underdamped oscillatory motion. (JN)

Describes a three-hour experiment designed to introduce students to chemistry of the angiotensis-converting enzyme, illustrate design of a quenched fluorescence substrate, and examine considerations necessary in designing a clinical assay. Includes background information on the biochemistry of hypertension, reagents/materials needed, procedures…

Suggesting that the evolutionary record may be written in proteins and genes, discusses research in which species are compared by immunology, DNA, and radioimmunoassay. Molecular studies show that DNA from humans and chimps is 98 percent identical, a degree of similarity usually occurring only among animals of the same genus. (JN)

Describes an experiment in which static/dynamic properties of a helical, steel spring are investigated. During the experiment students discover that the behavior of the springs is non-Hookean at small loads. Background information (including static deflection and period of oscillation) and typical results are provided. (JM)

Background information and laboratory procedures are provided for an undergraduate experiment requiring students to prepare a coordination compound. (SK)

Using ascorbic acid enzyme assays in conjunction with chronoamperometric measurements, reliable values for the principal electroactive components in the rat caudate extracellular fluid were established. Techniques used in the study are discussed. (JN)

Discusses fern life cycle and basic techniques for culturing fern gametophytes in the classroom. Also discusses investigations into the reproductive biology of ferns and into the early development of gametophytes. (JN)

A linear photodiode array is used as the photodetector element in a new ultraviolet-visible detection system for high-performance liquid chromatography (HPLC). Using a computer network, the system processes eight different chromatographic signals simultaneously in real-time and acquires spectra manually/automatically. Applications in fast HPLC…

Five papers presented at the Seventh Biennial Conference on Chemical Education (Stillwater, Oklahoma 1982) focused on qualitative analysis curricula and instruction. Topics included benefits of qualitative analysis, use of iodo/bromo-complexes in qualitative analysis schemes, lecture demonstrations, and brief descriptions of three courses. (JN)

An apparatus is described in which effects of pressure, volume, and temperature changes on a gas can be observed simultaneously. Includes use of the apparatus in demonstrating Boyle's, Gay-Lussac's, and Charles' Laws, attractive forces, Dalton's Law of Partial pressures, and in illustrating measurable vapor pressures of liquids and some solids.…

Describes modification of a chemical reaction to a single 4 1/2-hour laboratory period. Reaction kinetics between 2, 4-initrochlorobenzene and piperidine to form 2, 4-dinitrophenyl-piperidine and piperidinium hydrochloride are followed conductometrically at three temperatures to obtain data to calculate activation parameters. (Author/JN)

Three experiments using merocyanine M suitable as an integrated laboratory experience for undergraduates are described. Experiments demonstrate: complete molecular cycle composed of photochemical, thermal, and protolytic reaction steps; kinetics of cis-trans isomerization of the dye; and mechanism of base catalysis for thermal isomerization of the…

Effect of the "polarity" of low-polarity solvents on the amount of swelling produced in a solid polymer (demonstrated in an organic chemistry lecture) is also suitable as a laboratory experiment. Students can be assigned to a small group of solvents from the list provided. Procedures and materials needed are included. (Author/JN)

Some inherent instrument capabilities/limitations can be described in terms of signal to noise ratio (S/N). Two three-hour experiments are described to give students appreciation of the importance of signal strength and noise level in instrument performance and how S/N can be increased by choice of conditions and data manipulation. (Author/JN)