It is not conceivable that in a mixture or compound a component may exist in a negative ratio. Traditionally, therefore, a negative value could not be plotted on triangular coordinates. However, negative values are explicitly allowed, and the results extend the use of triangular coordinates as shown in this article. (JN)

Discusses the use of graph theory to aid in the depiction of organic molecular structures. Gives a historical perspective of graph theory and explains graph theory terminology with organic examples. Lists applications of graph theory to current research projects. (ML)

Describes two spreadsheets for producing acid-base titration curves, one uses relatively simple cell formulae that can be written into the spreadsheet by inexperienced students and the second uses more complex formulae that are best written by the teacher. (JRH)

The NASA CONNECT series features 30-minute, instructional videos for students in grades 5-8 and teacher's guides that use aeronautics and space technology as the organizing theme. In this guide and videotape, National Aeronautics and Space Administration (NASA) researchers and scientists use measurement, ratios, and graphing to demonstrate the…

Presents a method for graphically illustrating Le Chatelier's principle, suitable for the general chemistry undergraduate. (CS)

Three mathematics software packages, MathCAD, Point Five, and TK Solver Plus, are described and compared. The packages were rated on the accompanying documentation, ease of learning, ease of use, matrix operations, equation solving capability, versatility, use of units, generation of graphs and tables, readability of output, and overall…

Explains an activity which can be used to compare the effect of temperature on the rate of chemical reactions to the metabolic reactions that take place within the body. Outlines directions and materials needed to perform the experiment. Lists a number of the body's defenses against extremely low temperatures. (RT)

Demonstrated in this article are some of the capabilities of a spreadsheet program using data obtained in gas law experiments and a computer interface system. The ability to organize and analyze data which a computer can provide for the student is emphasized. (KR)

Described is a computer software package suitable for teaching and research in the area of multicomponent vapor-liquid equilibrium. This program, which has a complete database, can accomplish phase-equilibrium calculations using various models and graph the results. (KR)

Described are several spreadsheet templates which use the functions of iteration and logical look-up which allow students to calculate and graph quantum mechanical functions and to simulate rotational and vibrational energy level and spectra. The templates are listed in the appendix. (KR)

Discussed are the possible uses of spreadsheets in the undergraduate curriculum in chemical engineering classes. The advantages and flexibility of spreadsheets, spreadsheet instruction, graphing capabilities, assignment examples, and conclusions are described. (KR)

An activity in which students obtain a growth curve for algae, identify the exponential and linear growth phases, and calculate the parameters which characterize both phases is described. The procedure, a list of required materials, experimental conditions, analytical technique, and a discussion of the interpretations of individual results are…

Describes a freshman chemistry experiment designed to introduce scientific methodology, provide practice in measurement skills, and illustrate a fundamental chemical relationship (conservation of volume). Provides the experimental design, a materials and equipment list, sample calculations, and results. (JM)

Described is a membrane experiment that provides students with experience in fundamental engineering skills such as mass balances, modeling, and using the computer as a research tool. Included are the experimental design, theory, method of solution, sample calculations, and conclusions. (KR)

Investigates ground state electron configurations for some common elements using graphical methods. Bases observed tendencies on following ideas: "occupancy of differing shells, occupancy of differing subshells within a given shell, double occupancy vs. single occupancy of an orbital, and quantum-mechanical exchange." (ML)