The time-resolved fluorescence experiment investigating the halide quenching of fluorescence from quinine sulfate in water is described. The objectives of the experiment include reinforcing student understanding of the kinetics of competing pathways, making connections with microscopic theories of kinetics through comparison of experimental and…

Nanometer-scale investigations offer the potential of providing first-principles understanding of tribo-systems in terms of fundamental intermolecular forces. Some of the basic issues and motivation for use of scanning probes in the area of nanotribology is presented.

A new sympathetic ink that produces a violet color upon development was developed to develop chemical demonstrations using consumer chemicals. The demonstration was to have a simple, relatively safe reagent system that could be used to make a brightly colored, highly visible "magic sign" for use in science outreach programs.

Despite density differences, oil and water get along just fine when it comes to these experiments. This article explores the relationship between oil and water and provides brief experiments (including materials needed; procedure instructions; and evaluative questions) relating to: making layers with liquids; dropping a few objects in a tall glass…

An increased understanding of olfaction and gustation has underlined the critical importance of these two chemical senses in determining how humans respond to their environment. In this article, recent advances in chemosensory research are summarized. The use of a smell identification test, an odor discrimination test, and a test for anosmia to a…

This study examined whether online tool support for regulation promotes student learning during collaborative inquiry in a computer simulation-based learning environment. Sixty-one students worked in small groups to conduct a scientific inquiry with fluid dynamics. Groups in the experimental condition received a support tool with regulatory…

Hydrogen is a very important industrial gas in chemical processes. It is very volatile; therefore, it can escape from the process units and its mass balance is not always correct. In many industrial processes where hydrogen is reacted, kinetics are often related to hydrogen pressure. The right thermodynamic properties of hydrogen can be found for…

Students investigate energy conversions by collaborating to develop a free standing track of plastic tubing through which a ball bearing moves at the fastest possible speed. Friendly competition leads to discussion of what worked and did not work and to the identification and investigation of underlying principles. (Contains 4 charts.)

The presentations that will enable students to perform a side-by-side comparison of two conditions and gain better understanding of reactions at equilibrium are illustrated. A novel stoichiometric criterion for identifying equilibria that shift left upon addition of reactant is derived.

The Dumas method provides a relatively simple way to determine the molar mass of volatile chemical compounds. A potential source of error in the Dumas molar mass method as it is often practiced in introductory chemistry laboratories is reported.

A passive sampler that provides a convenient, simple, and fast method for nitrogen dioxide determination is proposed. The experiment can be modified for determinations of other air pollutants like formaldehyde and sulfur dioxide for hands-on experience for students studying environmental pollution problems.

The effect of some parameters on sulfurous acid and sulfur oxidation kinetics such as initial concentration of sulfurous acid, oxygen, TiO[2] crystalline concentration, the power of black light, and quantity of TiO[2] is investigated. The experiments can be performed in an undergraduate physical chemistry laboratory with an inexpensive…

An experiment to demonstrate the use of ethylene ketal as a protecting group, one that can be completed in four lab periods, is described. The hydroxy ketone like 4-hydroxy-4, 4-diphenyl-2-butanone formed during the reaction can be identified by its melting point, IR, and (super 1)H NMR.

An experiment is demonstrated to determine the percentage of oxygen in air using a pretreated piece of steel wool, which is an alternative to spectroscopic kinetic analysis. Students are able to determine the order of reaction for oxygen in its reaction with the iron in steel wool, and are able to use the existing technology to collect and analyze…

A detailed examination of a commonly accepted practice in geology offers an example of how to stimulate critical thinking, teaches students how to read reactions, and challenges students to formulate better experiments for determining mineral ages more accurately. A demonstration of a Potassium-Argon radiometric method for dating minerals is…