In this paper, we take a look at two electrostatics problems concerning hemispheres. The first problem concerns the direction of the electric field on the flat cap of a uniformly charged hemisphere. We show that the symmetry and principle of superposition coupled with Gauss's law gives a delightfully simple solution and then go on to examine how…

A simple experiment is described that permits advanced undergraduates to learn the principles and applications of the cavity ring down spectroscopy technique. The apparatus is used for measurements of low concentrations of NO[subscript 2] produced in air by an electric discharge. We present the setup, experimental procedure, data analysis and some…

In this work, we present a simple analysis of binary diffraction gratings with different slit widths relative to the grating period. The analysis is based on a simple phasor technique directly derived from the Huygens principle. By introducing a slit phasor and a grating phasor, the intensity of the diffracted orders and the grating's resolving…

Clock reactions based upon competing oxidation and reduction reactions of iodine and starch as the most popular type of chemistry example is presented to illustrate the redox phenomena, reaction kinetics, and principles of chemical titration. The examination of the photophysical principles underlying the iodine fluorescence quenching clock…

The conceptual understanding of Archimedes' principle can be verified in experimental procedures which determine mass and density using a floating object. This is demonstrated by simple experiments using graduated beakers. (Contains 5 figures.)

Various water-alcohol and alcohol-alcohol based experiments are used to demonstrate how the quartz-crystal microbalance (QCM) technique is used for measuring the viscosity of a system. The technique is very advantageous, as it is inexpensive and provides digital output.

A lab practical exam for second-year organic chemistry is presented that tests multiple lab skills and theory that the students have acquired directly from laboratory experiences. This exam motivates students to learn lab skills and is an effective end-of-term test for many of those skills. (Contains 2 figures.)

We present a new laboratory experiment on the photochemistry of organometallic [eta][superscript 5],[eta][superscript 6]-mixed-sandwich compounds, which is suitable for both the physical chemistry and inorganic chemistry laboratory. Specifically, students use 1,10-phenanthroline to trap the intermediate formed when…

The Radish Party inquiry is designed to teach the importance and relevance of soil organic matter to young students. In this investigation, students grow radishes in three different kinds of soils: sand, sand plus nutrients, and potting soil (soil that includes organic matter). The experience described here was conducted with first- and…

The experiment demonstrating the feasibility of using water as a solvent for organic reactions which highlights the cost and environmental benefits of its use is presented. The experiment encourages students to think in terms of the reaction mechanism of the oxidation of aldehydes knowing that potassium persulfate is the active oxidant in Oxone…

Preparation of phenylmagnesium bromide described by Eckert, addition of three equivalents of Grignard reagent to diethyl carbonate to form triphenylmethanol and a series of GC-MS procedures that form intermediates. The analysis is consistent with a gas chromatogram and mass spectrum for each of the expected intermediates and final product of the…

The recently introduced integrative guided-inquiry experiment explains various fundamental chemical concepts related to different biologically relevant molecules like resveratrol. The results of the photoisomerization of the molecule show that it is a very effective chemopreventative agent that can extend the lifespan in several organisms.

Thin-layer chromatography (TLC) is a very simple and effective technique that is used by chemists by different purposes, including the monitoring of the progress of a reaction. TLC can also be easily used for the analysis and identification of various acid-base indicator dyes.

The exocharmic reactions that can be observed microscopically are discussed. The students can discover the optimal concentration of an acidic lead nitrate solution, so that a crystal of potassium iodide, nudged to the edge of a drop, results in glinting golden hexagons of lead iodide.

A simple laboratory exercise is illustrated that exposes students to wide range of separation techniques in one laboratory program and provides a nice complement to a project-oriented program. Students have learned the basic principles of syringe filtration, centricon, dialysis, gel filtration and solid-phase extraction methodologies and have got…