The exocharmic reactions that can be observed microscopically are discussed. The students can discover the optimal concentration of an acidic lead nitrate solution, so that a crystal of potassium iodide, nudged to the edge of a drop, results in glinting golden hexagons of lead iodide.

The present volume was compiled by the AAPT Committee on Apparatus for Educational Institutions and by the AAPT-AIP Center for Education Apparatus in Physics to assist physics departments in the never-ending task of keeping their undergraduate laboratories up to date. The purpose of the book is to put before physics teachers for their…

Describes a method for using nuclear magnetic resonance to observe the effect of electronegativity on the chemical shift of protons in similar compounds. Suggests the use of 1,3-dihalopropanes as samples. Includes sample questions. (MVL)

Uses paper chromatography with food dyes to provide a simple and inexpensive basis for teaching chromatography. Provides experimental methodology and tabled results. Includes a solvent system comparison (Rf) for seven dyes and twenty-two solvents. (MVL)

An exercise is presented which demonstrates the determination of sample purity by differential scanning calorimetry. Data and references are provided to enable the exercise to be carried out as a dry-lab experiment. (BB)

The sequential-injection analysis (SIA) is an approach to sample handling that enables the automation of manual wet-chemistry procedures in a rapid, precise and efficient manner. The experiments using SIA fits well in the course of Instrumental Chemical Analysis and especially in the section of Automatic Methods of analysis provided by chemistry…

A guided-inquiry exercise conducted in both the lecture and laboratory components of a college introductory chemistry course for non-science majors is described. The exercise gave students the opportunity to independently determine the relationship between the temperature of water in an aluminum soda can and the intensity of implosion upon placing…

The three-step synthesis of Geodken's macrocycle, H[subscript 2]C[subscript 22]H[subscript 22]N[subscript 4], (5,14-dihydro-6,8,15,17-tetramethyldibenzo[b,i]-[1,4,8,11] tetraazacyclotetradecahexane), in an overall yield of 65% is described. By utilizing the synthesis of the macrocycle's dichloride salt, H[subscript 2]C[subscript 22]H[subscript…

A greener, microwave-assisted Wittig reaction has been developed for the second-semester organic teaching laboratory. Utilizing this microwave technique, a variety of styrene derivatives have been successfully synthesized from aromatic aldehydes in good yields (41-68%). The reaction not only occurs under neat reaction conditions, but also employs…

The reactivity and orientation effects of a substituent are analyzed by using HPLC to determine the competitive nitration of the benzene-toluene and benzene-fluorobenzene mixtures. The results have shown that HPLC is an excellent instrumental method to use in analyzing these mixtures.

Describes an experiment that provides a study of the different colors and shapes of crystals of transition metal dimethylglyoxime complexes with the use of a low power microscope. Discusses the preparation and examination of the crystals. (CW)

This article describes how a gas chromatograph may be used to determine the amount of carbon dioxide in exhaled air. The experiment has been used as part of a demonstration exercise at a local science fair and proved of interest to all age groups. (Author/BB)

Briefly outlines the theoretical basis of the phenomenon of photoconductivity and describes a simple experiment which demonstrates the photoconductive properties of cadmium sulfide. (JR)

Variations in science lab design can differentially impact student learning. Quantification of these differential impacts can be used in modeling--an approach we term "optimal lab design." In this study we estimated relative influences of six characteristics of lab design on students' attitudes toward science labs in three different…