We present an adaptation to an experiment previously published in this "Journal". The experiment was designed to determine the heat capacity ratios of gases by measuring the speed of sound using a modified Kundt's tube. The experiment yielded excellent results for all of the gases and gas mixtures measured. Although elegant in its simplicity, it…

Students in the second-semester organic chemistry laboratory perform a Wittig reaction between butylidenetriphenylphosphorane (an ylide) and benzaldehyde and determine the relative percentages of the cis and trans isomers of the 1-phenyl-1-pentene product. Because of the highly reactive nature of this unstabilized ylide, students are introduced to…

Although hydrogen-oxygen balloon explosions are popular demonstrations, the acoustic impulse created poses a hearing damage risk if the peak level exceeds 140 dB at the listener's ear. The results of acoustical measurements of hydrogen-oxygen balloons of varying volume and oxygen content are described. It is shown that hydrogen balloons may be…

A hands-on activity and demonstration, both applicable to the 2010 National Chemistry Week theme of Behind the Scenes with Chemistry, are presented. In the activity, students compare and contrast the properties of heat conductors and heat insulators. During the demonstration, students learn that water absorbed by a superabsorbent polymer can…

A pencil lead successfully served as an electrode for the determination of ascorbic acid in commercial orange juice. Cyclic voltammetry was used as an electrochemical probe to measure the current produced from the oxidation of ascorbic acid with a variety of electrodes. The data demonstrate that the less expensive pencil lead electrode gives…

In recent years, biofuel development and use has risen significantly. This undergraduate laboratory experiment educates students on the various alternative fuels that are being developed for automotive applications and the advantages and disadvantages of each. Students replicate commercially available alternative fuels, E85 and biodiesel, as well…

We developed an experiment suitable for an advanced inorganic chemistry laboratory that utilizes a cooperative learning environment, which allows students to develop an empirical method of determining the bonding mode of a series of unknown metal-thiocyanate complexes. Students synthesize the metal-thiocyanate complexes and obtain the FT-IR…

2D [superscript 1]H NOESY NMR spectroscopy is routinely used to give information on the closeness of hydrogen atoms through space. This work is based on a 2D [superscript 1]H NOESY NMR spectrum of a 12 base-pair DNA duplex. This 6-h laboratory workshop aims to provide advanced-level chemistry students with a basic, yet solid, understanding of how…

In this experiment, the concentrations of copper and zinc in brass are obtained by two methods. This experiment does not require advanced instrumentation, uses inexpensive chemicals, and can be easily carried out during a 3-h upper-level undergraduate laboratory. Pedagogically, the basic concepts of analytical chemistry in solutions, such as pH,…

Students commonly test the effects of chemical agents on the heart rate of the crustacean "Daphnia" magna, but the procedure has never been optimized. We determined the effects of three concentrations of ethanol, nicotine, and caffeine and of a control solution on heart rate in "Daphnia." Ethanol at 5% and 10% (v/v) reduced mean heart rate to…

This paper describes a very simple exercise using an inverted test tube pushed straight down into a column of water to determine the free-fall acceleration "g". The exercise employs the ideal gas law and only involves the measurement of the displacement of the bottom of the "diving bell" and the water level inside the tube with respect to the…

The temperature dependence of the dielectric permittivity is taken into account to study the energy change in a capacitor that follows a cycle between a cold and a hot thermal reservoir. There is a net energy gain in the process that, in principle, can be transformed into usable work. The paper is simple enough as to be used with keen…

This paper deals with temperature variations over time of objects placed in a constant-temperature environment in the presence of thermal radiation. After a historical introduction, the paper discusses cooling and warming laws, by taking into account first solely object-environment energy exchange by thermal radiation, and then adding…

An experiment is described that illustrates how chemical engineering correlations are created. Balls of different diameters and different specific gravities (all less than one) are dropped from several heights into a pool of water, and the maximum depth reached by the ball is measured. This data is used to estimate the coefficients for a…

This quasi-experimental study explores how student cumulative situational interest, short-term preference generated by particular conditions such as novel experiences can be developed into better individual interest, an enduring predisposition to engage in certain activity such as chemistry lessons. A continuous intervention of integrating novelty…