Describes a scheme that uses precipitation, gas evolution, complex ion formation, and flame tests to analyze for the following ions: Hg(I), Hg(II), Sb(III), Cr(III), Pb(II), Sr(II), Cu(II), Cd(II), As(III), chloride, nitrate, and sulfate. (MLH)

Discusses recent progress in using tunable lasers to selectively separate substances at the atomic and molecular level. Emphasizes biological applications, such as selective excitation and breaking of hydrogen bonds in DNA. (MLH)

Discusses the stability of the three-electron bond from a thermodynamic and kinetic standpoint using molecular orbital theory. (MLH)

Discusses the nomenclature of inorganic oxo acids in which the central atom is bonded to one or more organic residues; also considered are their salts and esters. (MLH)

Discusses the feasibility of analytical experiments that use only spot plates and eye droppers, thus allowing quantitative experiments to be performed with quantitites limited to several milliliters per student. (MLH)

Describes an experiment that involves the synthesis of copper (II) aspirinate and the analysis of copper content in the product using electrogravimetric, spectrophotometric, and titrimetric methods. (MLH)

Describes a laboratory experiment dissolving zinc from galvanized nails in which data can be gathered very quickly for statistical analysis. The data have sufficient significant figures and the experiment yields a nice distribution of random errors. Freshman students can gain an appreciation of the relationships between random error, number of…

Describes an outdoor scientific demonstration of metal reduction, a reaction known as the thermit process. Heat from an ignition mixture is required to initiate the reaction, which then becomes self-sustaining. The demonstration provides a dazzling introduction to such fundamental general chemistry topics as oxidation-reduction, metallurgy,…

Describes a quick, inexpensive laboratory demonstration of Charles's Law. The opening of a large, round balloon is placed snugly over the mouth of a narrow-mouthed 750-mL Erlenmeyer flask, which is then heated in a strong flame. At end of the full procedure, students easily arrive at the conclusion that the volume of a gas is proportional to…

Le Chbtelier's Principle states that, when a system at equilibrium is subjected to stress, the system will respond in such a way as to minimize the effect of the stress. Describes a lecture demonstration that illustrates shifts in the position of equilibrium caused by a variety of factors. The equilibrium mixture contains iron (III) and…

Heat changes in a lecture setting can be safely shown on an overhead projector using a simple and inexpensive apparatus. Heat evolution can be observed on a projector with adapted digital thermometers or by illuminating the red fluid in nonmercury thermometers. Describes a setup for doing this as well as a collection of demonstrations involving…

Describes a novel demonstration of the acid-base chemistry of the aluminum ion. (DKM)

A paramagnetic substance is attracted by a magnetic field with a force proportional to its magnetic susceptibility which is related to the number of unpaired electrons in the atoms. Data are used to establish oxidation states and bonding properties. Describes a simple setup to demonstrate the paramagnetism of common inorganic compounds. (DKM)

Argues that patterns of student flow between two- and four-year institutions are not linear and that the permutations of student situations affect the datasets that are used to both defend and question the effectiveness and transferability of two-year programs. (DDR)

States a convenient algorithm for temperature scale conversions and shows how performing the successive steps improves the accuracy of the results. (DDR)