This case was developed for a sophomore organic chemistry lab to illustrate how a combination of techniques is usually required in the identification of chemical compounds. It involves a murder mystery with a forensic twist: Two bodies have been recovered from two different lakes, but because of a mix-up at the morgue, the coroner is unable to…

A laboratory experiment for undergraduate physical chemistry courses that uses the experimental technique of dielectric relaxation spectroscopy to study molecular mobility in a crystal is proposed. An experiment provides an excellent opportunity for dealing with a wide diversity of important basic concepts in physical chemistry.

A laboratory experiment that emphasizes the interpretation of both infrared (IR) and nuclear magnetic resonance (NMR) spectra in the elucidation of the structure of an unknown compound was developed. The method helps students determine [to the first power]H- and [to the thirteenth power]C-NMR spectra from the structures of compounds and to…

A study combined 1D (one-dimensional) and 2D (two-dimensional) NMR spectroscopy to solve structural organic problems of three unknowns, which include 2-, 3-, and 4-heptanone. Results showed [to the first power]H NMR and [to the thirteenth power]C NMR signal assignments for 2- and 3-heptanone were more challenging than for 4-heptanone owing to the…

An alternative method that uses a simple apparatus to measure vapor pressure versus temperature in a closed system, in which the total pressure is the vapor pressure of the liquid sample, is described. The use of this apparatus gives students a more direct picture of vapor pressure than the isoteniscope method and results have generally been quite…

A detailed investigation of the clay-catalyzed condensation of sesamol and other phenols with 3-methyl-2-butenal to give methylenedioxyprecocene (MDP) and other chromenes is presented. The clay-catalyzed microwave-assisted condensation of sesamol with 3-methyl-2-butenal is appropriate for incorporation into undergraduate organic laboratory…

A microscale experiment in which the simultaneous oxidation of an organic compound and the reduction of a metal ion are photocatalytically performed in an aqueous slurry containing TiO[subscript 2] irradiated with UV light. This experiment can be performed in the laboratory session with simple chemicals and equipments.

The application of Lewis concept that provides students opportunity to predict and understand reaction behavior and themes in introductory chemistry of structure-property relationships of atoms, ions, and molecules is narrated. The general sequence takes the student through atomic structural theory, electronic configuration, periodicity, chemical…

This study investigates sequential dependencies in interresponse times (IRTs) produced by human subjects under random-ratio (RR) and staircase stochastic reinforcement of waiting (staircase SRW) schedules using autocorrelation and relative frequencies of IRT[subscript n] *IRT[subscript n+1] pairs. In the first of two experiments conducted for this…

Contingencies of reinforcement specify how reinforcers are earned and how they are obtained. Ratio contingencies specify the number of responses that earn a reinforcer, and the response satisfying the ratio requirement obtains the earned reinforcer. Simple interval schedules specify that a certain time earns a reinforcer, which is obtained by the…

Herrnstein's hyperbola describes the relation between response rate and reinforcer rate on variable-interval (VI) schedules. According to Herrnstein's (1970) interpretation, the parameter "r[subscript e]"represents the reinforcer rate extraneous to the alternative to which the equation is fitted (the target alternative). The hyperbola is based on…

"ARL" is the bimonthly report on research library issues and actions from ARL (Association of Research Libraries), CNI (Coalition of Networked Information), and SPARC (Scholarly Publishing and Academic Resources Coalition). "ARL" reports on current issues of interest to academic and research library administrators, staff, and…

The purpose of this study was to compare and contrast laboratory simulations with traditional (equipment) explorations in physics to determine differences, if any, in student achievement and changes in attitude toward science. Based upon the investigations conducted in undergraduate physics classes with 96 students who were non-science majors, it…

Two experiments examined the restriction of referential domains during unscripted conversation by analyzing the modification and online interpretation of referring expressions. Experiment 1 demonstrated that from the earliest moments of processing, addressees interpreted referring expressions with respect to referential domains constrained by the…

Intermolecular forces play an important role in many aspects of chemistry ranging from inorganic to biological chemistry. These forces dictate molecular conformation, species aggregation (including self-assembly), trends in solubility and boiling points, adsorption characteristics, viscosity, phase changes, surface tension, capillary action, vapor…