The addition of a dilute solution of bromine in carbon tetrachloride to a compound to test for carbon-carbon multiple bonds, which is one of the widely cited qualitative tests employed in organic chemistry is presented. Major advantages of this approach include the ease and rapidness of the procedure, the stability of the test solution over time,…

A thin-wall disposable Pasteur pipet is used as a vacuum-tight receptacle for air-sensitive compounds to ascertain their melting points. This technique is easy, economical, and successfully used for many years to develop air-sensitive samples for melting point determinations.

The preparation of libethenite, a double salt of copper(II) phosphate and copper(II) hydroxide presents the opportunity to discuss the prevalence of double salts in the environment, the relationship between solubility and stability in aqueous solution, the origin of the color of transition metal compounds and gravimetric analyses. Typical results…

A laboratory experiment designed to examine the entrance and exit effects in small electrochemical filter-press reactors used in the laboratory is presented. The single compartment of the filter-press reactor is filled with different turbulence promoters to study their influence as compared to the empty configuration.

The S[subscript N]2 reaction of 1-bromohexane and 1-bromobutane with potassium acetate is introduced to address the shortage of suitable laboratory experiments in organic laboratory. The experiment offers a review of some common laboratory techniques including the use of infrared spectroscopy to identify functional groups, the use of GC-MS…

We describe two bioinformatics exercises intended for use in a computer laboratory setting in an upper-level undergraduate biochemistry course. To introduce students to bioinformatics, the exercises incorporate several commonly used bioinformatics tools, including BLAST, that are freely available online. The exercises build upon the students'…

We describe experiments on Benard-Marangoni convection which permit a useful understanding of the main concepts involved in this phenomenon such as, for example, Benard cells, aspect ratio, Rayleigh and Marangoni numbers, Crispation number and critical conditions. In spite of the complexity of convection theory, we carry out a simple and…

In this undergraduate physical chemistry laboratory experiment, students acquire a high-resolution infrared absorption spectrum of carbon dioxide and use their data to show that the rotational-vibrational state populations follow a Boltzmann distribution. Data are acquired with a mid-infrared laser source and infrared detector. Appropriate…

Note is presented on the standard lab from a second year chemistry course. The lab "Determining which of the Seven FD&C Food-Approved Dyes are Used in Making Green Skittles", familiarizes students with the operation of the CHEM2000 UV-Vis spectrophorometer.

A circuit board analysis of the atomic absorption spectroscopy, which is used to measure lead content in a course for nonscience majors, is being presented. The experiment can also be used to explain the potential environmental hazards of unsafe disposal of various used electronic equipments.

A laboratory experiment that provides students a hands-on introduction to the specific techniques of liquid chromatography-tandem mass spectrometry (LC-MS/MS) and electrospray ionization is presented. The students can thus practice the analytical principles of sample extraction, detection, quantification, and quality control using a fresh fish…

We report three experiments that investigated whether the linguistic behavior of participants in a dialogue is affected by their role within that interaction. All experiments were concerned with the way in which speakers choose between syntactic forms with very similar meanings. Theories of dialogue assume that speakers address their contributions…

In 3 experiments, the authors compared duration judgments of filled stimuli (tones) with unfilled ones (intervals defined by clicks or gaps in tones). Temporal generalization procedures (Experiment 1) and verbal estimation procedures (Experiments 2 and 3) all showed that subjective durations of the tones were considerably longer than those of…

It is now widely accepted that sensitivity to goal-directed actions emerges during the first year of life. However, controversy still surrounds the question of how this sensitivity emerges and develops. One set of views emphasizes the role of observing behavioral cues, while another emphasizes the role of experience with producing own action. In a…

Four experiments were conducted to study the contents of human instrumental conditioning. Experiment 1 found positive transfer between a discriminative stimulus (S[superscript D] and an instrumental response (R) that shared the outcome (O) with the response that was originally trained with the S[superscript D], showing the formation of an…