Since activity coefficients are difficult even for good students to understand from the normal presentations in undergraduate physical chemistry, the author has reanalyzed this concept and presents a new way for introducing it. A practice problem (with solution) is included. (JN)

Discusses equilibrium distribution functions and provides an alternative "derivation" that allows the student, with the help of a computer, to gain intuitive insight as to the nature of distributions in general and the precise nature of the dominance of the Boltzmann distribution. (JN)

Provides background information on the use of back-titrations in complexometric quantitative analysis. Directions for planning back-titrations (based on the background information) are included. (JN)

Reports on the development of an equation that relates, quantitatively and continuously, bond order and bond length for any homo- and heteronuclear bond. (JN)

Reviews analogies used to try to capture the concept of the magnitude of Avogadro's number, including analogies related to small/tiny objects, counting, people, water, and money. Also presents several new ones which are based on modern computers and printers. (JN)

Prolog is one of the most successful "very high level languages." Describes this programming language (a product of artificial intelligence research) and attempts to show how it functions by using some short examples to illustrate its essential features. (JN)

Describes a course which emphasizes the relationship between chemistry and a student's daily life and between chemistry and his/her major (art or communications). Includes course outline and information on course content, student projects, source material, and teaching methods. (JN)

Describes the Dominican Study of Environmental Adaptation of Marine Organisms ("D.SEA"). Includes information organization and funding, purpose and goals, preliminary experiences with the program, and comments by the 14 students who have been working in the program. (JN)

The unit basis approach to problem solving analyzes a question in such a way that the student clearly sees what data are needed to solve the problem. Two examples are presented to illustrate the approach. (JN)

Procedures for preparing density gradient columns for chemical displays are presented. They include displays illustrating acid-base reactions, metal ion equilibria, and liquid density. The lifetime of these metastable displays is surprising, some lasting for months in display cabinets. (JN)

"Bench Remarks" is a new series dealing with chemical transformations of descriptive chemistry. The series begins with brief descriptions of several experiments with flames in an article titled "Flames: A Demonstration Lecture for Young Students and General Audiences" by Henry A. Bent. (JN)

Highlights difficulties that occur when teachers attempt to devise new experiments (use of hydrogen peroxide decomposition) and how seemingly useless results can be turned into productive student projects. Considers effects of ions present in tap water, pH, dust, and nature of vessel's surface. Reaction order and safety precautions are noted. (JN)

Job's method of continuous variations is a commonly used procedure for determining the composition of complexes in solution. Presents: (1) a review of the method; (2) theory of a new procedure for measuring Job's plots; and (3) an undergraduate experiment using the new method. (JN)

Background information/theory, procedures used, and typical results obtained are discussed for a system in which kerosene, water, and 2,4-dinitrophenol (DNP) are used to demonstrate the principles of liquid-liquid extraction in a Graesser rotary contractor. The DNP is almost equal between the two disimilar solvents. (JN)

Describes an experiment which offers a simple means of generating the liquidus curve of a temperature-composition diagram for a binary mixture of volatile liquids. Includes background information, materials list, procedures used (which can be accomplished by beginning organic chemistry students), and typical results obtained. (JN)