The molecular basis of evolution is an important and challenging concept for students to understand. In a previous article, we provided some of the scientific background necessary to teach this topic. This article features a series of laboratory activities demonstrating that molecular events can alter the genomes of organisms. These activities are…

In these two classroom demonstrations, students observe the reaction between H[subscript 2] gas and Pd foil. In the first demonstration, hydrogen and palladium combine within one minute at 1 atm and room temperature to yield the non-stoichiometric, interstitial hydride with formula close to the maximum known value, PdH[subscript 0.7]. In the…

The aim of this experiment is to study and calculate the kinetic constant of a Heck reaction: the arylation of but-3-en-2-ol by iodobenzene catalyzed by palladium acetate in presence of triethylamine in DMF. The reaction leads to a mixture of two ketones. Students use GC analysis to quantify reagents and products of reaction. They control the…

The series of experiments proposed for advanced undergraduate students deal with both standard organometallic preparative methods in dry anaerobic conditions and with a kinetic study of the mechanisms operating in the substitution of square-planar complexes. The preparation of organometallic compounds is carried out by transmetallation or…

The creative application of low-cost, readily available materials and techniques promotes inclusion and provides accessibility in the classroom and laboratory for students who are blind or have low vision. Difficulties encountered by these students include operation of laboratory equipment, execution of ordinary laboratory procedures, and use of…

Kinetics constitutes a core topic in both the lecture and laboratory components of lower- level chemistry courses. While textbook examples can ignore issues of time, temperature and safety, the laboratory can not. Reactions must occur slowly enough to be detected by students, occur rapidly enough for data collection in the few hours assigned to a…

Describes the nature and capabilities of methods used to characterize protein and peptide structure, indicating that they have undergone changes which have improved the speed, reliability, and applicability of the process. Also indicates that high-performance liquid chromatography and gel electrophoresis have made purifying proteins and peptides a…

Background information, procedures used, and results obtained are provided for an experiment in which a phase diagram is determined using a differential scanning calorimeter. Commercial samples of D-camphoric anhydride (Eastman Kodak) and D,L-camphoric anhydride (Aldrich) were used in the experiment. (JN)

Describes two frequently used DNA sequencing methods: Sander's enzymatic dideoxy method and Maxam and Gilbert's chemical sequencing method. Indicates that studying these methods provides students with knowledge of the chemical structure of DNA and how DNA sequence data are obtained. (JN)

Examines four processes involving homogeneous catalysis which highlight the contrast between the simplicity of the overall reaction and the complexity of the catalytic cycle. Describes how catalysts provide circuitous routes in which all energy barriers are relatively low rather than lowering the activation energy for a single step reaction.…

Discussed is an analytical technique that uses photons from lasers to resonantly excite an electron from some initial state of a gaseous atom through various excited states of the atom or molecule. Described are the apparatus, some analytical applications, and the precision and accuracy of the technique. Lists 26 references. (CW)

Considered are the underlying ideas of nucleophilic substitution and some of the misconceptions regarding this topic. Discusses methods for teaching this topic and includes definitions for key ideas and terms. (Author/CW)

Discusses modifications in the fatty acid monolayer experiment to reduce the inaccurate moleculary data students usually obtain. Copies of the experimental procedure used and a Pascal computer program to work up the data are available from the authors. (JN)

Background information and procedures are provided for a demonstration of intramolecular versus intermolecular hydrogen bonding. The demonstration is based on structural changes in bilirubin molecules which lead to changes in physical properties. A list of further investigations to try is included. (JN)

Describes current methods for the synthesis of DNA. Also describes the use of DNA as a highly specific molecular probe and as an agent for the mutation of genes. (DH)