Describes this reaction sequence involving reactivity and synthesis of heterocycles: (1) synthesis of 2,4,6-triphenylpyrylium tetrafluoroborate, II; (2) its reaction with nucleophiles; (3) reaction of pyrylium salt II with a primary amine (benzylamine, p-methoxybenzylamine, and furfurylamine) to form the N-substituted-2,4,6-triphenylpyridinium…

Errors in determining the effectiveness of mouthwashes, disinfectants, and other household products as antibacterial agents may result from using broth cultures and/or irregularly shaped bits of filter paper. Presents procedures for a better technique and, for advanced students, two additional procedures for introducing quantitative analysis into…

Reports results in the attempted synthesis of the ethyl ester hydrochlorides of 21 common L-amino acids. Procedures used in the synthesis are outlined. (JN)

Background information and experimental procedures are provided for the multistep synthesis of frontalin. The experiment exposes students to a range of practical laboratory problems and important synthetic reactions and provides experiences in working on a medium-size, as well as a relatively small-size scale. (JN)

Describes a series of experiments (requiring six hours/week for six to eight weeks) involving the synthesis and methanolysis of substituted benzyl tosylates. The experiments provide students with experiences in kinetic data manipulation and an introduction and firm basis for structure-activity relationships and solvent effects in organic…

Discusses a graphical procedure which allows the distribution constant of iodine to be determined simultaneously with the trihalide anion stability constant. In addition, the procedure extends the experimental chemistry from distribution equilibria to important thermodynamic and bonding features. Advantages of using the procedure are also…

Describes an experiment in which the kinetics of dimerization of nitrosamine induced by a flash of light is measured. The experiment can be performed with a commercial ultraviolet-VIS spetrophotometer with easy to make modifications. The experiment demonstrates a flash photolysis system not always available in university chemistry laboratories.…

Background information and procedures used are provided for the synthesis of 4,5-diphenyl-methylimidazole. This experiment on the chemistry of heterocycles is ideally suited for beginning undergraduate organic chemistry students. (JN)

Describes a project-type experiment in which students each try to find the color indicator present in a particular flower. The philosophy of conducting such an experiment and procedures used are included. (JN)

Research on reflective teaching is reviewed in the areas of: its benefits; the Exxon Educational Foundation Project; students' ability to think and talk critically about teaching and learning; identification of variables during the act of teaching; perceptions of teaching; conceptual development and modes of thinking; and the self-concept,…

Describes a computer program that students use to check their suggestions of possible lines of investigation during a microbiology exercise, the results of procedures, and the decisions made on the basis of experimental evidence. Effectiveness of the program and practical aspects of the investigation are considered. (DH)

Background information, materials needed, and procedures used are provided for potentiometric fluoride, halide, orthophosphate, and sulfate titrations. Typical results obtained are also provided for each type of titration. (JN)

Background information, procedures used, and typical results obtained are provided for a simple homogeneous precipitation preparation of chromium(II) acetate. (JN)

Although the cost of basic science to the taxpayer is only about five percent of the cost of applied research and development, it contributes deeply to technology, the education of scientists, and the general enrichment of the culture. Examples of such research are provided to illustrate these contributions. (JN)

Discusses direct chemical information that can be obtained from modern nuclear magnetic resonance (NMR) methods, concentrating on the types of problems that can be solved. Shows how selected methods provide information about polymers, bipolymers, biochemistry, small organic molecules, inorganic compounds, and compounds oriented in a magnetic…