This course presents the student with a performance approach to biology. Each technique is covered in standard lecture format and in guided, independent laboratories. Examinations and grading are competency-based and require knowledge of both the use and limitations of the techniques. (BB)

Two papers are reported on, one dealing with a course on inorganic reaction mechanisms for college seniors, and the other on the set-up necessary to provide students with an automatic potentiometric titration facility. (BB)

An alternative development of the quadratic formula via paper squares and rectangles is presented. A physical model is constructed to demonstrate the constant term needed to complete the square. (MP)

This article describes how a gas chromatograph may be used to determine the amount of carbon dioxide in exhaled air. The experiment has been used as part of a demonstration exercise at a local science fair and proved of interest to all age groups. (Author/BB)

Describes procedures to demonstrate oxidation and simultaneous equilibria involving insoluble salts. (SL)

Described are nine enzyme essays for distinguishing soil samples. Colorimetric methods are used to compare enzyme levels in soils from different sites. Each soil tested had its own spectrum of activity. Attention is drawn to applications of this technique in forensic science and in studies of soil fertility. (Author/AJ)

Shows how the Archimedes method is used to determine the density of a single crystal of ammonium oxalate monohydrate. Also shows how to calculate the density of other chemicals when they are available as single crystals. Experimental procedures and materials needed are included. (JN)

Reports a consecutive first-order reaction for which the concentrations of reactant, intermediate, and products can be determined simulataneously. This reaction is the epoxidation of 2,5-di-tert-butyl-1,4-benzoquinone (I) by alkaline hydroperoxidation using tert-butyl hydroperoxide and benzyltrimethylammonium hydroxide (Triton B) catalyst.…

Explains an experiment in which the rotation of a patch of skin on a tadpole results in a frog with rotated spots, proving that the spot pattern is determined long before it becomes visible. Procedures used are included. (DH)

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)

Background information, procedures used, and typical results obtained are provided for an experiment in which students determine and compare the Arrhenius activation energies (Ea) for the hydrolysis of salicin. This reaction is subject to catalysis both by acid and by the enzyme emulsin (beta-d-glucoside glycohydrolase). (JN)

Indicates that the true red color of calcium can be obtained (using the procedure described by Sorm and Logowski) if the calcium ion solution is mixed with an equal volume of saturated ammonium bromide solution. Suggestions for flame tests of other elements are also noted. (JN)

Shows that nitric acid can be used as a rapid, versatile, and economical oxidant for selected organic substances. The experiments (with background information, procedures, and results provided) require one three-hour laboratory period but could serve as open-ended projects since substrates not described could be oxidized. (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)

Describes this reaction sequence involving reactivity and synthesis of heterocycles: (1) synthesis of 2,4,6-triphenylpyrylium tetrafluoroborate, II; (2) its reaction with nucleophiles; (3) reaction of pyrylium salt II with a primary amine (benzylamine, p-methoxybenzylamine, and furfurylamine) to form the N-substituted-2,4,6-triphenylpyridinium…