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.

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.

A study has shown that methylation of 1,8-dihydroxy-9,10-anthraquinone (1) with methyl tosylate is highly dependent upon reaction conditions. When the reaction is carried out by a simple heating of the reaction mixture without solvent it yields dimethyl product in a nearly quantitative yield and refluxing the same mixture of reactants in…

The near daily news reports on food-borne diseases caused by contaminated produce, dairy, or meats suggests to the public that the safety of the U.S. food supply is in jeopardy. These reports, as well as a general distrust in federal agencies due in part to mad cow disease and toxigenic forms of "E. coli" in ground beef, have resulted in an…

A laboratory exercise is presented in which students determine where metabolic heat is primarily generated in blooming eastern skunk cabbage ("Symplocarpus foetidus") plants. Students consider how color, shape, and orientation of spathes, and stage of flower maturation, may affect metabolic heat production and retention of both metabolic and solar…

This field exercise examines the feeding preferences of Gray Squirrels ("Sciurus carolinensis"). Students present squirrels with a variety of food types in a cafeteria-style arrangement in order to test hypotheses about foraging preferences. This exercise, which is appropriate for introductory biology, ecology, and animal behavior classes, is…

The purpose of this study was to reconstruct writers' reasoning process as reflected in their written texts. The codes resulting from the text analysis were related to cognitive operations, ranging from simple to more sophisticated ones. The sequence of the cognitive operations as the text unfolded represents the writer's cognitive pathway at the…

Active-learning strategies are increasingly being integrated into college-level science courses to make material more accessible to all students and to improve learning outcomes. One active-learning pedagogy, case-based learning (CBL), was developed as a way to both enhance engagement in the material and to accommodate diverse learning styles.…

Investigates which factors are important in revising chemistry laboratory experiments to enhance student interest and enjoyment of experimental science. Findings indicate the importance of several factors including varied content, real-world connections, items from outside the student's usual range of experience, well-paced experiments, error-free…

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…

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…

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 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.

A real-life experience that provides an ideal opportunity to combine problem-solving skills, critical thinking, and collaborative learning is described in the content of a realistic instrumental analysis laboratory. This practical experiment can be used in an instrumental analysis or analytical course.