Salicylic acid and its derivative, acetylsalicylic acid, are often encountered in introductory organic chemistry experiments, and mention is often made that salicylic acid was originally isolated from the bark of the willow tree. This biological connection, however, is typically not further pursued, leaving students with an impression that biology…

This experiment describes a discovery-based method for the regio- and stereoselective hydrochlorination of carvone, appropriate for a 3-h second-semester organic chemistry laboratory. The product is identified through interpretation of the [superscript 13]C NMR and DEPT spectra are obtained on an Anasazi EFT-60 at 15 MHz as neat samples. A…

This laboratory experiment describes the preparation of a N-protected phenylalanine ethyl ester by a zinc-mediated Mannich-like multicomponent reaction between benzyl bromide, "p"-anisidine, and ethyl glyoxylate. The one-step reaction involves the in situ metallation of benzyl bromide into a benzylzinc reagent and its addition onto imine (Barbier…

Some balls which are made of high-quality rubber (an elastomeric) material, such as tennis or squash balls, could be used for the determination of an important property of such materials called resilience. Since a bouncing ball involves a single impact we call this property "rebound resilience" and express it as the ratio of the rebound height to…

Photocatalytic water splitting by semiconductor photocatalysts has attracted considerable attention in the past few decades. In this experiment, nanosized titanium dioxide (nano-TiO[subscript 2]) particles are used to photocatalytically split water, which is then monitored by an oxygen sensor. Sacrificial reagents such as organics (EDTA) and metal…

An investigation of the Blue Bottle Experiment, a well-known lecture demonstration reaction involving the dye-catalyzed air oxidation of a reducing sugar in alkaline solution, has delineated the sequence of reactions leading to the bleaching of the dye, the regeneration of color, and so forth. Enolization of the sugar is proposed as a key step in…

In this experiment, students learn how to find the unknown concentration of sodium acetate using both the graphical treatment of standard addition and the standard addition equation. In the graphical treatment of standard addition, the peak area of the methyl peak in each of the sodium acetate standard solutions is found by integration using…

This laboratory experiment, using proton NMR spectroscopy to determine the dissociation constant for heterocyclic bases, has been modified from a previously described experiment. A solution of a substituted pyridine is prepared using deuterium oxide (D[subscript 2]O) as the solvent. The pH of the solution is adjusted and proton NMR spectra are…

The measurement of trace levels of bisphenol A (BPA) leached out of household plastics using solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS) is reported here. BPA is an endocrine-disrupting compound used in the industrial manufacture of polycarbonate plastic bottles and epoxy resin can liners. This experiment…

The potential of replacing petroleum fuels with renewable biofuels has drawn significant public interest. Many states have imposed biodiesel mandates or incentives to use commercial biodiesel blends. We present an inquiry-driven experiment where students are given the tasks to gather samples, develop analytical methods using various instrumental…

An alternative analytical method for measuring the kinetic parameters of the enzymes invertase and lactase is described. Invertase hydrolyzes sucrose to glucose and fructose and lactase hydrolyzes lactose to glucose and galactose. In most enzyme kinetics studies, photometric methods or test strips are used to quantify the derivates of the…

A directed study for the undergraduate physical chemistry laboratory for determining the transference number of H[superscript +](aq) using a modified moving boundary method is presented. The laboratory study combines Faraday's laws of electrolysis with mole ratios and the perfect gas equation. The volume of hydrogen gas produced at the cathode is…

General chemistry students often have difficulty writing balanced equations and performing stoichiometry calculations for precipitation reactions, in part because of difficulty understanding the symbolic notation used to represent chemical reactions. We have developed a problem-based experiment to improve student learning of these concepts, and…

Details are given for the conversion of an inexpensive webcam to a camera specifically sensitive to the near infrared (700-1000 nm). Some experiments and practical applications are suggested and illustrated. (Contains 9 figures.)

I will propose here a kinematic approach for measuring the drag coefficient of rotational symmetric objects falling through liquids. For this, I will show that one can obtain a measurement of the drag coefficient of a rotational symmetric object by numerically solving the equation of motion describing its fall through a known liquid contained in a…