Experiments involving the coupling of alkyl and aryl halides in the presence of lithium metal and ultrasound are described. The experiments illustrate classical Wurtz and Fittig reactions in addition to being a convenient application of organic sonochemistry. (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)

The semipermeability of biological membranes is simply and directly illustrated in an experiment which uses ovolecithin liposomes as convenient models for biological membranes. Background information and procedures used are provided. (JN)

Reviews three functions performed by modern computing integrators: (1) data acquisition; (2) data processing; and (3) communication. Also shows with examples how new electronic components enhance the functions of this popular analytical instrument in those areas. (JN)

Describes a precipitation experiment which follows a yellow powder experiment discussed in part 1 (vol 62 no 3 p238-40). Advantages of using a Petri dish to perform the experiment, laboratory procedures used, instructional strategies, and implications for chemistry curriculum and instruction are discussed. (JN)

Examines mechanisms related to use of N-bromosuccinimide (NBS) for bromination at an allylic position. Also presents derived rate laws for three possible reactions of molecular bromine with an alkene: (1) free radical substitution; (2) free radical addition; and (3) electrophilic addition. (JN)

Kinetic versus thermodynamic control of product formation is discussed in undergraduate textbooks, and journal papers suggest suitable experiments to illustrate this concept. In rationalizing experimental observations, this paper offers a new alternative to that conventionally employed and provides students with an interesting exercise in…

Discusses: (1) characteristic initial velocity behavior (considering the five-step reaction sequence for rapid equilibrium-order bisubstrate mechanisms); (2) dead-end inhibition; (3) inhibition by single products; and (4) an activator as a leading reactant. (JN)

Examines energy interconversions in photosynthesis, limiting the discussion to areas pertinent to chemistry (particularly the energetics of the light reactions). Topic areas considered include bioenergetics, photochemistry, conversion of light energy into electrical potential energy, the chemiosmotic hypothesis, and others. (JN)

The 17 rare earth elements account for one-fifth of the 83 naturally occurring elements and collectively rank as the 22nd most abundant "element." Properties of these elements (including their chemical similarity), their extraction from the earth, and their uses are discussed. (JN)

Describes: (1) a FORTH-language, computer-controlled potentiometric titration; (2) coulometric titrations using computer-interfaced potentiometric endpoint detection; (3) interfacing a scanning infrared spectrophotometer to a microcomputer; (4) demonstrations of signal-to-noise enhancement (digital filtering); (5) and an inexpensive Apple…

Shows that the rules of thumb for propagating significant figures through arithmetic calculations frequently yield misleading results. Also describes two procedures for performing this propagation more reliably than the rules of thumb. However, both require considerably more calculational effort than do the rules. (JN)

Describes inservice chemistry enrichment courses and programs offered by the University of Alabama in Birmingham. They include academic year programs, mini-term courses, technique courses, special interest courses, special format courses, travel-study programs, and special workshops and conferences. Preservice chemistry teacher programs are also…

First-year college chemistry students (N=359) were surveyed to determine how high school chemistry prepared them for college chemistry and to make recommendations to high school students preparing to take college chemistry. Survey results and recommendations are presented. (JN)

Describes two one-week chemistry courses for intermediate-grade children and the principles upon which the courses are based. Includes course outlines which give course content, sequence, and the amount of time spent on each activity. (JN)