Describes the use of phase transfer conditions to prepare a sulfur and phosphorus ylide. Background information and procedures are provided for the experiment (which can be completed in one three-hour laboratory period). (JN)

Presented are procedures used to assay the activity of lipase during storage at three different temperatures. Since lipase solutions can decay even when refrigerated, it is recommended that the enzyme be freshly prepared prior to laboratory sessions in which they are used. (JN)

Provides procedures to measure the calcium concentration in fruit juice by atomic absorption. Fruit juice is used because: (1) it is an important consumer product; (2) large samples are available; and (3) calcium exists in fruit juice at concentrations that do not require excessive dilution or preconcentration prior to measurement. (JN)

Although it is a major synthetic reaction, the Wittig reaction has not been used in undergraduate laboratories due to the potential hazard and difficulty associated with the preparation/use of the strong bases needed to generate the required ylides. Procedures are presented for an experiment in which these difficulties are avoided. (JN)

Describes an experiment which shows: (1) how measurements of the reaction electromotive force for the cell (Pt/glass/NaCl(aq,m),buffer/AgCl/Ag/Pt) can be utilized in determining the absolute pH of the buffer; and (2) the demonstration of the use of the Debye-Huckel model of an electrolyte solution in solving an important electrochemical problem.…

Describes an experiment in which undergraduate students can do simple Huckel Molecular Orbital (HMO) calculations from spectral data for a series of four closely related dyes. (JN)

Discusses the theory of resonance Raman (RR) spectroscopy as it applies to beta-carotene and lycopene pigments (found in tomatoes and carrots, respectively). Also discusses an experiment which demonstrates the theoretical principles involved. The experiment has been tested over a three-year period and has received excellent acceptance by physical…

Background information, procedures, and typical results obtained are provided for two demonstrations. The first involves the colorful complexes of copper(II). The second involves reverse-phase separation of Food, Drug, and Cosmetic (FD & C) dyes using a solvent gradient. (JN)

Background information (including relevant chemical reactions), procedures used, and results obtained are provided for the synthesis and characterization of a macrobicyclic complex. The synthesis can be completed within two to three hours and is inexpensive and safe. Suggestions for further experiments are included. (JN)

Procedures are provided for experiments containing complex ions with octahedral symmetry, hexaamminecobalt(III) chloride and hexaamminechromium(III) nitrate, so students can interpret fully the ultra violet/visible spectra of the complex cations in terms of the ligand field parameters, 10 "Dq," the Racah interelectron repulsion parameters, "B,"…

Presented is a three-hour instrumental analysis experiment which allows study of software data-handling methods. These methods include sampling, boxcar averaging, smoothing, ensemble averaging, and digital filtering. Use of the program should provide students with a better idea of advantages and disadvantages of using such software data-handling…

Describes a procedure for determining ethane-1,2-diamine (EN) which is generally applicable for inert or labile complexes or for EN in its salts, although it cannot be used directly with ammonium or coordinated ammonia. It gives results with five percent accuracy or better and requires less than one hour laboratory time. (JN)

Provides the National Science Teachers Association guidelines to enrich education by encouraging students to observe living organisms and to learn proper respect for life. Major areas include: care and responsibility for animals in the classroom; experimental studies of animals in the classroom; and research investigations involving vertebrate…

Describes how a computer simulation is used with a laboratory experiment on the synthesis of urea in isolated hepatocytes. The simulation calculates the amount of urea formed and the amount of ammonium remaining as the concentrations of ornithine, citrulline, argininosuccinate, arginine, and aspartate are altered. (JN)

Background information, procedures, and results obtained are provided for two experiments. One measures the field strength at a particular moment to an accuracy with a level of error less than two percent. The other gives continuous readings or potentials in the field. (JN)