Describes an experiment on the simultaneous determination of chromium and magnesium by spectophotometry modified to include the Generalized Standard Addition Method computer program, a multivariate calibration method that provides optimal multicomponent analysis in the presence of interference and matrix effects. Provides instructions for…

Describes a microscale laboratory course in which students perform many classic organic reactions using only one-hundredth to one-thousandth the amount of starting material usual in student experiments. Reduction of toxic chemicals concentration in laboratory air and savings in chemical costs and experimental time are benefits of the novel course.…

Previously described a class experiment which employs the hydraulic analog to represent systems of first order reactions in batch reactors. The hydraulic experiments are extended to represent reaction systems with nonlinear systems. (JN)

As part of a project focusing on techniques in industrial chemistry, students carry out experiments on separating copper from cobalt in chloride-containing aqueous solution by liquid extraction with triisoctylamine solvent and search the literature on the separation process of these metals. These experiments and the literature research are…

Background information (including optical properties of inorganic materials) and procedures are provided for an experiment which introduces students to preparation of a doped semiconductor; phosphorescence; gettering procedures; reducing atmospheres; and use of a high-temperature furnace with associated thermocouples, temperature controllers, and…

Examines techniques used to make ultrasensitive spectroscopic measurements. They include excitation, thermal lens, photo acoustic, and ionization spectroscopies. Guidelines and methods are provided for each technique; common uses and applications are explained. (DH)

Describes an apparatus developed for photochemical studies, particularly those involving the fluorescence of halogenated acetones. The apparatus is constructed from equipment normally found in a moderately sized physical chemical laboratory. Also provides background information on some aspects of the photophysics of halogenated propanones. (JN)

Describes a set of experiments (for senior-level biochemistry students) which permit evaluation and estimation of rate and equilibrium constants involving an intermediate in the alpha-chymotrypsin mediated hydrolysis of ortho-hydroxy-alpha-toluenesulfonic acid (I). The only equipment required for the experiments is a well-thermostated double beam…

The advantages of DNA hybridization procedures for classroom and clinical use can now be realized by the recent development of nonradioactive DNA labeling/detection procedures. These methods (which are described) can replace the use of isotopes in standard DNA hybridization procedures. (JN)

Suggests a simple technique for collecting and observing human hair roots to compare structure, function, and variation. Students extract their own hair samples and view them using a 40-power microscope objective. Differences between active/inactive phases of hair growth are readily observed. (The activity can be adapted for younger students.) (DH)

Project CHEMLAB has prepared a database which focuses on laboratory experiments suitable for high school through graduate or professional school levels. The scope of the project, the structure of the database, database features, and computer searching are discussed. (JN)

The value of the genus Nematodius in teaching is not widely realized. Presented is a brief biological outline of the organism (including geographical distribution and reproductive cycle/behavior) and its use in student investigation of selective predation. (Author/JN)

Described are filming of laboratory activities in 14 classes to determine class movement time, pupil centered activity time, and teacher centered activity time. Proportions of times ranged as follows: movement, 4-21 percent; pupil centered, 29-85 percent; teacher centered, 11-64 percent. (SL)

Procedures are described for showing the effectiveness of antibiotics (penicillin, ampicillin, and tetracycline) against a nonpathogenic bacteria strain (Bacillus cereus). Methods are outlined for preparing nutrient agar, sterilizing tubes, pouring agar plates, preparing antibiotic discs, and transferring antibiotic discs to agar plates. (CS)

This study investigated the effect of two different approaches to practical work on the procedural understanding of foundation level students at two historically similar universities in South Africa, the University of Cape Town (UCT) and the University of the Witwatersrand (Wits), both of which run programs to improve the access of disadvantaged…