The rapid compression or expansion of a gas in a plastic syringe is a poor approximation of an adiabatic process. Heat exchange with the walls of the syringe brings the gas to equilibrium in an amount of time that is not significantly greater than the length of the compression or expansion itself. Despite this limitation, it is still possible to…

Beer's law is an ideal technique that works only in certain situations. A method for dealing with more complex conditions needs to be integrated into the analytical chemistry curriculum. For that reason, the capabilities and limitations of two common chemometric algorithms, classical least squares (CLS) and principal component regression (PCR),…

The creative application of low-cost, readily available materials and techniques promotes inclusion and provides accessibility in the classroom and laboratory for students who are blind or have low vision. Difficulties encountered by these students include operation of laboratory equipment, execution of ordinary laboratory procedures, and use of…

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 experiment in which static/dynamic properties of a helical, steel spring are investigated. During the experiment students discover that the behavior of the springs is non-Hookean at small loads. Background information (including static deflection and period of oscillation) and typical results are provided. (JM)

The Laboratory Structure and Task Analysis Inventory (LAI) is an instrument designed to facilitate the analysis of laboratory investigations in secondary school science. It yields a quantitative picture of the kinds of activities required of a student in performing laboratory investigations. The report includes guidelines for the use of the…

Described is an advanced undergraduate laboratory experiment in which radio-frequency transitions between molecular hyperfine structure states may be observed. Aspects of the quantum theory applied to the analysis of this physical system, are discussed. (Authors/BT)

Describes an experiment, designed for and tested in an advanced inorganic laboratory methods course for college seniors and graduate students, that prepares and analyzes several samples in the nearly ideal potassium perchlorate-permanganate solid solution series. The results are accounted for by a theoretical treatment based upon aqueous…

Describes an experiment that, using a commercially available solid-state selective electrode in conjunction with a pH-meter, determines the stability constants of sodium sulfate while varying the ionic strength of the media using sodium chloride. Detailed reproducible procedures of both the measurements and calculations are described. (BT)

Describes an experiment, designed for use in the undergraduate laboratory, that measures the bond energies of molecules using a small commercial mass spectrometer and low-cost digital voltmeters. (BT)

Contends that the nature of physics has been misrepresented by blurring or ignoring important distinctions between "errors" and "discrepancies" and that dealing with these and related problems can improve students' enjoyment of labs and understanding of physics. Nature of physics, role of experiments, experimental errors, and error analysis are…

Describes a student kinetic experiment involving second order kinetics as well as displaying photochromism using a wide variety of techniques from both physical and organic chemistry. Describes measurement of (1) the rate of the recombination reaction; (2) the extinction coefficient; and (3) the ESR spectrometer signal. (Author/JN)

Describes a laboratory technique for use in an undergraduate instrumental analysis course that, using the interpretation of window diagrams, prepares a mixed liquid phase column for gas-liquid chromatography. A detailed procedure is provided. (BT)