Discusses the effects of using carbon dioxide contaminated sodium hydroxide solution as a titrant for a solution of a weak monoprotic acid and the resulting distortion of the titration curve in comparison to one obtained when an uncontaminated titrant is used. (CW)

Examines the usefulness of cyclic voltammetry to the determination of a complex compound's stoichiometry. Discusses the experimental design, laboratory equipment, and results. (CW)

Reports a method of preparation for tris(ethylenediamine)cobalt(III) and tris(2,2'-bipyridine)cobalt(III) that will shorten the preparation time by approximately 3 hours. Notes the time for synthesis and isolation of compound one was 1 hour (yield 38 percent) while compound two took 50 minutes (yield 71%). (MVL)

Describes two demonstrations for college level chemistry courses including: "Electrochemical Cells Using Sodium Silicate" and "A Simple, Vivid Demonstration of Selective Precipitation." Lists materials, preparation, procedures, and precautions. (CW)

Describes experiments in which students prepare in situ soluble complexes of metal ions with different ligands and observe and estimate the change in formal potential that the ion undergoes upon complexation. Discusses student formation and analysis of soluble complexes of two different metal ions with the same ligand. (CW)

Describes a laboratory exercise in which acid dissociation constants and molecular weights are extracted from sample data and the sample is identified. Emphasizes accurate volumetric work while bringing to practice the concepts of acid-base equilibria, activity coefficients, and thermodynamic constants. (CW)

Describes an application of potentiometry to the determination of acidic and basic compounds in household cleaners in chemistry instruction. Discusses procedures and results of this experiment. (CW)

Describes a project that can be used to encourage intellectual independence in students and teach them some of the inquiry procedures used in scientific research. Discusses procedures, safety precautions, and sample results. (CW)

Provides the methodology put forth by Moore and Kraus to separate Co++ from Ni++ in an 8M HCl solution. Notes that cobalt(II) forms a wide variety of anionic complexes. Points out that as the solutions leave the exchange column the color bands of green, blue, and pink are easily seen. (MVL)

Describes a simplified redox method for total iron analysis suitable for execution in a three-hour laboratory period by general chemistry students. Discusses materials, procedures, analyses, and student performance. (CW)

Discusses a student exercise which requires the optimizing of the charring and atomization temperatures by producing a plot of absorbance versus temperature for each temperature parameter. Notes that although the graphite furnace atomic absorption spectroscopy technique has widespread industrial use, there are no published, structured experiments…

Gives upper level chemistry students a better understanding of the application of lasers in the field of spectroscopy. Provides three experiments to demonstrate the thermal lens effect: determination of beam profile, cell position optimization, and pKa determination. (MVL)

Describes a molar volume-molar mass experiment for use in general chemistry laboratories. Gives background technical information, procedures for the titration of aqueous hydrogen peroxide with standard potassium permanganate and catalytic decomposition of hydrogen peroxide to produce oxygen, and a discussion of the results obtained in three…

Describes a laboratory experiment designed for use in a freshman chemistry course. Considers the use of a set of known "training reactions" with a "training set" of solutions. (CW)

Shows how video recordings of the Brownian motion of tiny particles may be made. Describes a classroom demonstration and cites a reported experiment designed to show the random nature of Brownian motion. Suggests a student experiment to discover the distance a tiny particle travels as a function of time. (MVL)