Describes a sensitive, simple, and inexpensive microrespirator that may be used readily by students. Discusses materials and methods for construction and classroom applications. (LZ)

The laboratory has been given a central and distinctive role in science education, and science educators have suggested that rich benefits in learning accrue from using laboratory activities. Twenty years have been elapsed since we published a frequently cited, critical review of the research on the school science laboratory (Hofstein & Lunetta,…

An experiment in the parallel synthesis of azo dyes that demonstrates the concepts of structure-activity relationships and chemical diversity with vivid colors is described. It is seen that this experiment is suitable for the second-semester organic chemistry laboratory and also for the one-semester organic laboratory.

On equilibrium properties of aqueous solutions of sulfuric acid, Julius Thomsen has marked that the heat evolved on diluting liquid sulfuric acid with water is a continuous function of the water used, and excluded absolutely the acceptance of definite hydrates as existing in the solution. Information about thermochemical measurement, a discussion…

The role of ethanol O-d in nullifying the deuterolysis may be demonstrated by determining that transesterification of methyl acetoacetate of the ethyl ester occurs as well as deuterium exchange of the five acetoacetate hydrogens. The significant acidity of the methylene protons in the acetoacetate group, the efficacy of base catalysis, the role of…

A multisection undergraduate laboratory involving the microscale synthesis and spectroscopic analysis of unmetalled porphyrins and their corresponding metalloporphyins is described. The microscale synthesis involving the isolation of the metalloporphyrins as solids and their corresponding (super 1)H NMR spectra are presented.

A new undergraduate laboratory experiment suitable for demonstrating some key techniques used in natural products chemistry is described. A laboratory experiment is developed which in the process of extracting shikimic acid from star aniseed exposes students to a number of important experimental techniques.

When students use plants to investigate cellular respiration, they confront the misconception that plants only "perform" photosynthesis (Driver et. al., 1994). Because this is such a strong misconception, several experiences with plant respiration are needed before students accept the idea that plants use some of the food from photosynthesis. Part…

An experiment is performed to measure the relative gas-phase basicities of a series of five amino acids to compare the results to literature values. The experiments use the kinetic method for deriving ion thermochemistry and allow students to perform accurate measurements of thermodynamics in a relatively short time.

A group exercise, suggested to be most effective when used near the semester-end, enables entry-level students to appreciate the application of plant biology and makes botany labs experimental. It is believed that this series of labs helps students to appreciate their own learning when they teach and explain things to others.

The use of KOH and a phase transfer catalyst to achieve diastereoselective Darzens condensation is described and a modification of the method for use in organic chemistry is carried out. The experiment involves the condensation of t-butyl chloroacentate and p-tolualdehyde with KOH and benzyltriethylammonium chloride in THF.

The facile, high yielding synthesis of phenylsuccinamic acids is described and one of these syntheses, the reaction of phenylsuccinic anhydride with tert-butylamine, is successfully modified and adapted for use in the second-semester organic chemistry laboratory at St. John's University. Succinamic acids are compounds that contain both the amide…

A novel apparatus that strengthens the connection between research and teaching laboratories and serves multiple purposes is described. A versatile laser apparatus suitable for the undergraduate teaching laboratory that may serve as polarimeter, nephelometer or fluorimeter is designed.

An experiment which enables students to determine the index of refraction at various wavelengths is demonstrated by using two polymers examples, poly(dimethyl siloxane) (PDMS) and poly(methyl methacrylate) (PMMA). This experiment would be suitable for a course in organic chemistry or any course discussing the optical properties of polymeric…

One of those who failed to establish himself as a natural philosopher in 18th century Paris was the future revolutionary Jean Paul Marat. He did not only publish several monographs on heat, optics and electricity in which he attempted to characterise his work as being purely empirical but he also tried to establish himself as a public lecturer.…