Background information, procedures used, and typical results obtained are provided for an experiment in which the stability constants of unstable complexes are determined. (JN)

Provides background information and procedures for the multi-step synthesis of tiger moth and boll weevil pheromones (sex attractants). These syntheses require several laboratory periods. The tiger moth pheromone synthesis is suitable for introductory organic chemistry while the boll weevil pheromone is recommended for an advanced laboratory…

Describes a set of experiments (for senior-level biochemistry students) which permit evaluation and estimation of rate and equilibrium constants involving an intermediate in the alpha-chymotrypsin mediated hydrolysis of ortho-hydroxy-alpha-toluenesulfonic acid (I). The only equipment required for the experiments is a well-thermostated double beam…

Suggests that the preparation of 2-bromopentane from 2-pentanol might represent an instructive addition to a published description of pheromone synthesis in that it is economical, extends the synthetic nature of the problem, and amplifies the mechanistic vagaries of the substitution reaction. Theory, procedures used, and safety considerations are…

Describes a compact, digital voltmeter which exceeds, both in accuracy and input impedance, most commercial pH meters and potentiometers. The instrument consists of two parts: a very high impedance hybrid operational amplifier used as a voltage follower (ICH8500/A, Intersil) and a four and one-half digits LED display panel meter (RP-4500,…

Discusses six common problems which may occur when using temporary labels on chemicals, samples, or mixtures in teaching or research laboratories. Solutions to each of these problems are offered. (JN)

A gas chromatography (GC) mass spectroscopy (MS) system recently developed by Hewlett-Packard (HP-5987 GC/MS/Data System) is described, illustrating the technological advances that have been achieved with the system. Examples of the data processing and output process are provided to demonstrate the capabilities and application of the system to…

Several chemical concepts can be visualized by using deformation density maps. They often present convincing experimental confirmation and they should be incorporated into the chemistry curriculum dealing with bonding and molecular structure. Examples of the maps and quantitative information derived from research studies are presented. (JN)

The valence-shell electron-pair repulsion (VSEPR) theory is a useful tool for predicting molecular structures. The major stumbling block in teaching VSEPR theory for coordination numbers two through six is in explaining the arrangement of five electron pairs. The dilemma of five-coordination and implications for instruction in introductory…

Discusses the nature and role of models in various aspects of the chemistry curriculum, examining the purposes and importance of tangible, linguistic, arithmetical, thermodynamic, and quantum-physical models. Strategies in using models in laboratory work and in lecture demonstrations are also considered. (JN)

Nonlinear least squares computer programs are extremely valuable in fitting complicated equations to experimental data. They are easy to use and free students and teachers from the tedium of trying to derive linearized forms to complicated equations. The use of these programs (available for most medium/large scale computers) is discussed. (JN)

Presents a new method of uncertainty propagation which concentrates on the calculation of upper and lower limits (the "worst cases"), bypassing absolute and relative uncertainties. Includes advantages of this method and its use in freshmen laboratories, advantages of the traditional method, and a numerical example done by both methods. (JN)

Problems of equilibria in condensed phases (particularly those involving solutes in dilute solutions) are encountered by students in their laboratory work; the thermodynamics of these equilibria is neglected in many textbooks. Therefore, several aspects of this topic are explored, focusing on pressure dependence and choice of standard state. (JN)

Discusses reasons for teaching solution equilibrium in college and high school chemistry classes. Points out the most important aspects of this topic to consider at the elementary level and how (in a high school course) it is used as a transition topic, tying together other chemistry concepts presented. (JN)

Describes graphical solutions of equations for stirred-tank reactors in series; data management software for producing and searching customized mass spectral libraries; least squares and chromatography programs; a low-cost data acquisition system for Apple microcomputers; nuclear magnetic resonance interpretation with graphics; chemical bonding…