Explores different solubility processes and related issues, including the second law of thermodynamics and ideal mixtures, real liquids, intermolecular forces, and solids in liquids or gases in liquids. (Contains 22 references.) (ASK)

In three experiments using the barpress conditioned suppression task with albino rats, we studied the renewal (relapse) of conditioned fear in an ABA fear-renewal paradigm. We found that explicitly unpaired (EU) deliveries of conditioned stimuli (CSs) and unconditioned stimuli (USs) in Context B thwarted fear renewal in Context A. Evidence…

As heat sources go, the old standby for elementary and middle school science laboratories has been the centuries old alcohol lamp. Unfortunately, this inexpensive heat producer has been a continuous source of accidents--many of which are relatively serious. Hot plates are emerging as the most popular source of heat for science experiments. The…

The feasibility of using an optical mouse to track the viscoelastic deformation of low-density polyethylene films that have a fixed attached load is presented. It is seen that using an optical mouse and with rudimentary experiment paraphernalia and arrangement, it is possible to get good measurements of viscoelastic deformation.

The Diels-Alder reaction is used as an example for showing the integration of computational and preparative techniques, which help in demonstrating the physical organic concepts in synthetic organic chemistry. These experiments show that the students should not accept the computational results without questioning them and in many Diels-Alder…

Three alternative methods for performing flame tests using cheaply and easily available cotton swabs are described. These flame tests are useful for chemical demonstrations or laboratory experiments because they are quick and easy to perform with easy cleanup and disposal methods.

Experiments are conducted for spectroscopic analysis of the allyl esters of some aromatic carboxylic acids. It is understood that these experiments allow the students to monitor the effect of hydrogen bonding on the IR stretching frequencies for the hydroxyl and carbonyl groups and also provide them with an excellent opportunity to examine the…

Newly discovered biogenic organo halogens with an emphasis on the biologically active examples from marine organisms, bacteria, terrestrial plants and higher life forms, including humans, are focused. Organohalogen compounds represent a valuable and expanding class of natural products, in many cases boasting exceptional biological activity.

The unique experience of designing and conducting a reaction are afforded to the students in a similar way to what one would do in a research lab. It encouraged them to think about each procedural step and its purpose, by the discovery-based procedure.

The environmental significance of acid rain on water systems of different buffer capacities is discussed. The most prevalent natural buffer system is created by the equilibrium between carbonate ions and carbon dioxide.

The spontaneous mixing of helium and air in a helium-inflated balloon is described in an experiment in which the partial pressure of the gases in the balloon are determined from the mole factions and the total pressure measured in the balloon. The results described provide a model for teaching concepts of partial pressure, chemical potential, and…

A review of concepts like tunneling through a metal-molecule-metal-junction, contrast with electrochemical and optical-charge injection, strong-coupling limit, calculations of tunnel transport, electron transfer through Redox-active molecules is presented. This is followed by a discussion of experimental approaches for single-molecule measurements.

The student results are presented for the determination of vanillin in a vanilla extract as part of a problem-solving approach. The determination of the vanillin concentration in the Dutch product "Baukje vanilla extract" is described.

The Sciencenter Museum in Ithaca, New York, materialized from the idea of providing children and museum visitors with hands-on experience of simple chemical activities and puzzles. A brief description and evaluation of the ten fun-filled chemical activities, precautionary measures and management details, are presented.

In order to find the right combination to construct a cold pack for athletic injuries, students mix liquids and solids in a calorimeter, and use a thermometer to ascertain whether the chemical reaction is hot or cold. Many formulae for chemical reactions are given, the first of which is used for commercial cold packs.