In this article, we discuss the replication of a forgotten chemical instrument in the context of undergraduate chemistry education. Together with students, we have attempted to replicate an eighteenth century "eudiometrical" procedure. Eudiometry was the practice of measuring the "goodness" of the air by looking at the volume…

A simple photometric device was built to measure the kinetics of the title reaction. The device consisted of a green light-emitting diode (centered at 520 nm), a sample vial, a photodiode, and an Arduino microcontroller board. These parts were mounted on a black poly(lactic acid) holder which was manufactured by utilizing three-dimensional…

Almost all commercial quadrupole ICP-MS instruments use collision/reaction cells to either attenuate spectral interferences or shift the analyte of interest to an interference-free "m/z" (e.g., by O addition). A laboratory practical was developed to introduce the students to the basic operating principles of ICP-MS using a hands-on…

Gas chromatography-mass spectrometry (GC-MS) and GC-tandem MS (GC-MS/MS) are useful in many separation and characterization procedures. GC-MS is now a common tool in industry and research, and increasingly, GC-MS/MS is applied to the measurement of trace components in complex mixtures. This report describes an upper-level undergraduate experiment…

In this work, we described an image processing procedure for the measurement of surface tension of the air-liquid interface using isothermal capillary action. The experiment, designed for an undergraduate course, is based on the analysis of a series of solutions with diverse surfactant concentrations at different ionic strengths. The objective of…

Imines are important in biological chemistry and as intermediates in organic synthesis. An experiment for introductory undergraduate organic chemistry is presented in which benzaldehyde was condensed with "p"-methoxyaniline in toluene to give 4-methoxy-"N"-(phenylmethylene)benzenamine. Water was removed by azeotropic…

Industrial purification of biomolecules is commonly based on a sequence of chromatographic processes, which are adapted slightly to new target components, as the time to market is crucial. To improve time and material efficiency, modeling is increasingly used to determine optimal operating conditions, thus providing new challenges for current and…

Easily recoverable, thumb-sized pieces of high-density dry ice are conveniently produced by deposition of carbon dioxide within a test tube submerged in liquid nitrogen. A carbon dioxide-filled balloon sealed over the mouth of the test tube serves as a gas reservoir, and further permits a dramatic demonstration of both the gas-to-solid phase…

Describes an experiment demonstrating Lenz's law by measuring a magnet falling through a copper tube compared to a nonmagnet falling. Presents diagrams and pictures showing the apparatus. (YP)

Describes three experiments with an air table to produce a centripetal force. Provides some diagrams and pictures of the apparatus. (YP)

Introduces a method for two-dimensional kinematics measurements by hanging marbles with long strings. Describes experimental procedures for conservation of momentum and obtaining the coefficient of restitution. Provides diagrams and mathematical expressions for the activities. (YP)

Describes three activities: "Solar Approach to Ohm's Law," dealing with the Ohm's law and the inverse square law; "Using LED's to Demonstrate Induced Current," showing Faraday's law and Lenz's law by using light emitting diodes (LEDs); and "The Helium-Filled Organ Pipe," discussing a discrepancy between theory and experiment. (YP)

Presents an experiment to measure the threshold limit of the adhesion of water. Discusses types of thresholds and pseudo thresholds. Provides 13 examples of thresholds in science. (MVL)

Introduces a computer solution of the oscillation of a mass suspended by a spring in a viscous liquid. Describes the equations of motion, spreadsheet solution, copying the formulas, plotting the results, and extending the applications. Presents spreadsheet and physics formulas for the step-by-step solution and spreadsheet solution. (YP)

Describes an experiment to determine the density of air within a 10 percent error range using a basketball and a triple beam balance. Provides the typical data and a graph. (YP)