Introduced is a method for estimating carbon-13 nuclear magnetic resonance (NMR) shifts. The method is brief and simple so that students can use it with ease. (RH)

Discussed are a brief explanation of the function of the vortex tube and some applications for the chemistry laboratory. It is a useful and inexpensive solution to many small-scale laboratory heating and cooling applications. (RH)

Discussed are modifications in data analysis that allow Gran plot methodology to be extended to acidic or basic analyte solutions that would be difficult to treat by conventional equations. (RH)

Described are infrared windows made from Tupperware and polyethylene coffee can lids that provide acceptable spectra for low-frequency infrared. (RH)

Described is a quick, easy, and cheap, but effective method of obtaining infrared spectra of solids and nonvolatile liquids by Fourier transform infrared spectroscopy. The technique uses tissue paper as a support matrix. (RH)

Described is an alternative method to infrared spectroscopy for the quantification of xylene mixtures. The method employs nuclear magnetic resonance spectroscopy. (RH)

Described is an experiment to investigate the plasticizer content in polyvinyl chloride (PVC) products. The experiment is designed for college students using an instrumental analysis laboratory. (RH)

Described is a modified Fehling test and a modified corrected Benedict test. (RH)

Described is a teaching method for chemistry that gives college students practice in experimental design. Students are given a problem and required to design a procedure to solve the problem. Problems increase in complexity as the students progress through the courses. (RH)

Provides an overview of obsidian hydration dating for the instructor by presenting: (1) principles of the method; (2) procedures; (3) applications; and (4) limitations. The theory of the method and one or more laboratory exercises can be easily introduced into the undergraduate geology curriculum. (JN)

Describes a method suitable for quantitative studies of plant water status conducted by high school or college students and the calculation of the relative water content (RWC) of a plant. Materials, methods, procedures, and results are discussed, with sample data figures provided. (CS)

Described is an activity in which the life cycle of a plant is investigated over a 20-day period. Included are background information, a list of materials, procedures, diagrams of the plant, apparatus, and pollination. An outline is suggested. (CW)

Discusses the rationale for and use of minilabs (requiring from 15 to 90 minutes to complete) for freshmen chemistry experiments. Provides several examples, advantages for students and instructors, and results of a questionnaire evaluation completed by 83 students. (JN)

Describes an introductory laboratory format (used for 12 years at Colorado College) that involves students in the design and exploration phases of experiments. The laboratory features include choices of experiments; clearly explained goals; student selection of methods; wise equipment use; check-out procedures with instructor questions; and no…

Describes a two-hour physics laboratory experiment modeling the phenomena of eclipsing binary stars developed by the Air Force Academy as part of a week-long laboratory-oriented experience for visiting high school students. (BT)