Both a control group and experimental group (23 students each) received a lecture on direct current circuits; the experimental group also participated in a lab using a device explaining an analogy for electric current. The experimental group's posttest scores were much higher, indicating that the analogical device helped overcome student…

Describes a method for working with Coomassie Blue to analyze banding patterns of purified eukaryotic cell membrane proteins. (SAH)

Describes a laboratory experiment on the determination of the molecular weights of gases lighter than air. (YDS)

Presents an experimental procedure to measure the volume of a gas more accurately and which requires very common and inexpensive materials. (YDS)

Discusses the quality of textbooks, worksheets, and laboratory manuals and presents Project 2061's review of science and mathematics textbooks in the United States. (YDS)

Explains the qualities of a good laboratory experiment. (YDS)

The experiment of determination of the percent of oxygen in air is performed in a general chemistry laboratory in which students compare the results calculated from the pressure measurements obtained with the calculator-based systems to those obtained in a water-measurement method. This experiment allows students to explore a fundamental reaction…

Supercritical fluids (SCFs) possess properties that are intermediate between liquids and gases. The combination of supercritical fluid technology with advanced characterization techniques such as electron microscopy provided a practical and rewarding undergraduate laboratory experiment.

The polymerase chain reaction (PCR) is a Nobel Prize-winning technique that amplifies a specific segment of DNA and is commonly used to test for the presence of genetic modifications. Students use PCR to test corn meal and corn-muffin mixes for the presence of a promoter commonly used in genetically modified foods, the cauliflower mosaic virus 35S…

The disposal of hazardous chemicals and chemical containing products is of much concern and there is a need for a document that describes the hazards of a chemical, to consider the precautionary measures to be taken. Many classic demonstrations however cannot be performed due to safety concerns since sometimes chemicals are deemed too hazardous or…

A forensic project is described that is suitable for an undergraduate instrumental methods lab. Accelerants commonly used by arsonists are analyzed by static headspace enrichment followed by gas chromatography. The conditions used for headspace enrichment (e.g., time and temperature) are known to influence the distribution of hydrocarbons…

Theoretical and experimental evidence for the dependence of viscosities of the real gases on temperature is described, suggesting that this dependence is greater than that predicted by the kinetic theory of gases. The experimental results were obtained using common modern instrumentation and could be reproduced by students in analytical or…

The widely used method of synthesizing HCl and DCl gases for infrared analysis by hydrolysis of benzoyl chloride includes a potentially dangerous final step whereby the frozen product is allowed to heat and expand into an infrared gas cell. The subsequent rapid rise in vapor pressure can "pop" open glass joints in the vacuum line and vent the…

An experiment is conducted to ascertain trace-level Pb in samples of bovine liver or muscle by applying graphite furnace atomic absorption spectrophotometry (GFAAS). The primary objective is to display the effects of physical and spectral intrusions in determining trace elements, and project the usual methods employed to minimize accuracy errors…

The hazards of silver used in the laboratories are described for the benefit of the students and the teachers. The exposure limits and symptoms due to acute exposures are also mentioned.