Substances that deliver chemical messages between same/different species are called semiochemicals. Surveyed are three types of semiochemicals (pheromones, allomones, and kairomones), types of organisms involved, and specific chemicals used to carry the various kinds of messages. (JN)

Presented is a concise and critical account of developments in nonequilibrium thermodynamics. The criterion for stability of nonequilibrium steady states is critically examined for consecutive and monomolecular triangular reactions, autocatalytic reactions, auto-inhibited reactions, and the Lotka-Volterra model. (JN)

Provides and discusses an equation which, when combined with the well-known Ricci equation for oxyacids, results in a generally useful equation for dealing with acid dissociation experiments and analyses. (JN)

The concept of two-dimensional chirality is used to enhance students' understanding of three-dimensional stereochemistry. This chirality is used as a key to teaching/understanding such concepts as enaniotropism, diastereotopism, pseudoasymmetry, retention/inversion of configuration, and stereochemical results of addition to double bonds. (JN)

Describes a simple method to determine potential chemical formulas for a given molecular weight and to calculate all of the typical mass spectrometric parameters which can be obtained experimentally. Calculated values can then be compared to experimental values to obtain the most reasonable formula. (JN)

Most inorganic chemistry textbooks present the determination of spectroscopic terms obtained from a given electronic configuration by a method which requires explicitly writing down all microstates. A method is provided and discussed in which tabulating all possible microstates is not required. (JN)

Eleven separate reports on computer programs (with sources indicated) and related materials are presented. These include chemical applications of interactive function translator, numerical optimization on microcomputer, Apple pH meter, axes-drawing program for Hewlett-Packard digital plotters, inexpensive chart recorder for freshmen laboratory,…

Describes an eight-module, high school chemistry curriculum (including outline of course content) which encourages students to envision chemistry as a science based on general, related concepts rather than on a discipline composed of segmented, isolated topics. Module 1 objectives, assignments, laboratory experiences, and test are available from…

The British name for cooperative education is "sandwich courses," indicating the interpolation of academic studies and paid work experience periods. Discusses development of and current cooperative programs/experiences, Salford integrated sandwich courses, integrated chemistry courses, organization/assessment of industrial training performance,…

Discusses the chemical nature of gallstones and theories related to their formation. Also discusses experimental procedures used to identify chemical constituents of gallstones, indicating that cholesterol is found in almost 75 percent of stones examined. (JN)

Isobutylene is an important bulk chemical for the petroleum industry. Dimerization and hydrogenation reactions produce the standard fuel octane rating comparison. This classic chemistry is often misrepresented in modern texts, however, and this paper attempts to correlate the physical organic principles that apply. (Author)

Free radical chlorination of methane is used in organic chemistry to introduce free radical/chain reactions. In spite of its common occurrence, demonstrations of the reaction are uncommon. Therefore, such a demonstration is provided, including background information, preparation of reactants/reaction vessel, introduction of reactants, irradiation,…

An approach is described in which accurate weighings are provided under circumstances when samples cannot be placed directly on a balance pan. The approach, based on external weighing, uses a new simple apparatus designed for any kind of analytical balance and not requiring a hole through the base of the balance. (JN)

Describes an optical cell, suitable for high-pressure studies between at least -130 and +150 degrees Celsius, which may be assembled for about $50. Discusses experimental demonstration of principles involved when using the apparatus, including effects of pressure on coordination of ions in solution and on reaction rates in solution. (JN)

Discusses teaching strategies in the physical chemistry laboratory. These include taking students' personality factors into account, having students repeat the same investigation several times under partially changed conditions, presenting research problems for students to solve, and others. Indicates that approaches described may be suitable for…