Examines the phenomenon of water drops that float on water at room temperature. Describes experiments that have been done to study this phenomenon. (MA)

Discusses a successfully implemented laboratory experiment that compares the strengths and weaknesses of mechanical and computer models. The computer models used are available from the Quantum Chemistry Program Exchange (QCPE) at a modest price. (JN)

Provides an overview on biological electron-transfer reactions, summarizing what is known about how distance, spatial organization, medium, and other factors affect electron transfer. Experimental approaches, including studies of bimolecular electron transfer reactions (electrostatic effects and precursor complexes), are considered. (JN)

Background information, procedures used, and results obtained are provided for an experiment in which a phase diagram is determined using a differential scanning calorimeter. Commercial samples of D-camphoric anhydride (Eastman Kodak) and D,L-camphoric anhydride (Aldrich) were used in the experiment. (JN)

Describes an experiment involving use of a microemulsion and its characteristic thermal phase change to determine molecular weights of polyoxyethylene samples. The experiment provides students with background information on polymers and organized media and with experience in evaluating polymer molecular weight by using a unique property of a…

Describes an experiment in which undergraduate students can do simple Huckel Molecular Orbital (HMO) calculations from spectral data for a series of four closely related dyes. (JN)

Presents an activity in which students gather their own snowflake collection in search of matching crystals. Students stretch plastic wrap over embroidery hoops that provide a snowflake-catching surface. Snowflakes are viewed under a microscope and photographed. (MDH)

Discusses two different uses of information theory in chemistry to present entropy and chemical structure analysis. (GA)

Discusses modifications in the fatty acid monolayer experiment to reduce the inaccurate moleculary data students usually obtain. Copies of the experimental procedure used and a Pascal computer program to work up the data are available from the authors. (JN)

Discusses the rationale for using photochemistry to merge descriptive chemistry and molecular orbital theory in first-year chemistry courses. Includes procedures and safety information for various activities, demonstrations, and experiments involving photochemical reactions. (DH)

Describes an experiment to discover the topology of plasma membrane aminophospholipids (phosphatidylethanolamine and phosphatidylserine) using whole platelets and trinitrobenzene sulfonate (TNBS) as a probe. Reports changes in phospholipid distribution during platelet activation with simultaneous action of thrombia and collagen. Details the…

To make material on Raoult's law more meaningful, students complete exercises on paper, in the laboratory, and with molecular models. Paper exercises give practice using the law; laboratory work illustrates behavior of real solutions; and models show relationships between properties of individual molecules and of matter in bulk. (JN)

Liquid crystal displays are currently utilized to convey information via graphic displays. Presents experiments and explanations that employ the concept of liquid crystals to learn concepts related to the various states of matter, electric and magnetic forces, refraction of light, and optics. Discusses applications of liquid crystal technology.…

Describes a method designed to balance oxidation-reduction chemical equations. Outlines a method which is based on changes in the oxidation number that can be applied to both molecular reactions and ionic reactions. Provides examples and delineates the steps to follow for each type of equation balancing. (TW)

Three-phased learning cycles (exploration, invention, application) were introduced into general chemistry laboratories at Northland College (Wisconsin). Discusses each phase and its use in a learning cycle on the functional groups of organic compounds. (JN)