Describes a freshman chemistry experiment in which students separate and identify commonly used drugs by thin-layer chromatography. Materials needed, procedures used, and typical results obtained are included. (JN)

Describes a low-cost ($120) device which eliminates plasma lines in Raman spectra. The device consists of two prisms and two mirrors which are held in a symmetrical relationship to one another so that a particular position will allow only one wavelength to pass through on a given axis. (JN)

Describes a rapid, visual demonstration of protein separation by gel filtration chromatography. The procedure separates two highly colored proteins of different molecular weights on a Sephadex G-75 in 45 minutes. This time includes packing the column as well. Background information, reagents needed, procedures used, and results obtained are…

Describes a physical/organic chemistry experiment on conductance behavior of hydrogen-bonded species of six salts of easily accessible, nitrogen-containing bases and halogenoacetic acids. The bases and acids used are much cheaper and have comparatively less unpleasant odors than the pyrim puridines and trifluoroacetic acid used in previously…

Background information, procedures used, and typical results obtained are provided for an experiment involving the separation of chlorophyll a and chlorophyll b from their diastereomers. Reasons why the experiment can be easily integrated into most laboratory curricula where high-performance liquid chromatography capabilities exist are given. (JN)

Provides a method for correcting the photoemission from a collector when using the photoelectric effect experiment to determine Planck's constant. The problem results from a negative current through the cell and makes the measurement of the cutoff potential difficult. (DH)

Background information, materials needed, laboratory procedures, and typical results are provided for five high performance liquid chromatography experiments (three isocratic and two step gradient separations). Suggestions for further experimentation are also provided, including quantitative determinations and separation of charged solutes. (JN)

Background information (including chemical reactions) and procedures used are provided for (1) three buffer demonstrations and (2) a demonstration of phase transfer catalysis and carbanion formation. (JN)

Describes experiments in which students determine the ground state ionization constant (GSIC) by analyzing the absorption spectra of 2-naphthol in acidic, basic, and buffered solutions. Information on the ground and excited state ionization constants and on the kinetics of the excited state deprotonation-protonation reaction is included. (JN)

Background information, procedures used, and equipment needed are provided for an experiment in which a series of readily available, inexpensive, and relatively nontoxic phenols are separated using thin-layer chromatographic techniques. The experiment permits a discussion of how relative Rf values may be rationalized by considering a molecule's…

Job's method of continuous variations is a commonly used procedure for determining the composition of complexes in solution. Presents: (1) a review of the method; (2) theory of a new procedure for measuring Job's plots; and (3) an undergraduate experiment using the new method. (JN)

Determining the pounds of sodium chloride needed for a water softener to replace all the calcium/magnesium ions in a month's water supply for a typical local household is used as an exercise to integrate several chemistry concepts. The solution to this problem and suggestions for related laboratory experiments are offered. (JN)

Describes a physical chemistry experiment which allows such concepts as kinetics, catalysis, isotope shifts, coupling constants, and the use of nuclear magnetic resonance (NMR) for quantitative work to be covered in the same exercise. Background information, experimental procedures used, and typical results obtained are included. (JN)

The use of sodium acetate solution to show supersaturation is a favorite among lecture demonstrations. However, careful adjustment of the solute-to-water ratio must be made to attain the most spectacular effect--complete solidification of the solution. Procedures to accomplish this are provided and discussed. (JN)

A relatively simple opto-electronic setup is described that utilizes a cadmium sulphide (CdS) photoconductive cell to detect resonance of a stretched vibrating string or wire. The display may be either an oscilloscope or a frequency counter. Also describes an inexpensive socket for flanged-base light bulbs. (JN)