This experiment involves an esterification synthesis to study reaction kinetics where students explore these topics utilizing the sense of smell rather than the traditional approach of using spectroscopic methods. Students study the effects of various factors including the concentration of the carboxylic acid and the amounts of the catalyst or…

This exercise provides students hands-on experience with the topics of glycosidation, hemiacetal and acetal formation, proton nuclear magnetic resonance ([superscript 1]H NMR) spectroscopy, and kinetic and thermodynamic product formation. In this laboratory experiment, the methyl acetal of ribose is synthesized, and the kinetic and thermodynamic…

This article describes a comprehensive treatment of experimental enzyme kinetics strongly coupled to electronic data acquisition and use of spreadsheets to organize data and perform linear and nonlinear least-squares analyses, all in a manner that promotes development of important reasoning skills. Kinetic parameters are obtained for the stable…

Alcohol-based hand-rub sanitizers are the types of products that hospital professionals use very often. These sanitizers can be classified into two major groups: those that contain a large quantity of thickener, and thus are a gel, and those that contain a small quantity of thickener, and thus remain a liquid. In an effort to create a laboratory…

A pedagogical experiment is described to examine the physical absorption of gases, in this case carbon dioxide, in a hollow fiber membrane contactor (HFMC) where the absorption concentration profile can be followed by a color change. The HFMC is used to teach important concepts and can be used in interesting applications for students, such as…

Using macroscopic thermodynamics, the general law for adiabatic processes carried out by an ideal gas was studied. It was shown that the process reversibility is characterized by the adiabatic reversibility coefficient r, in the range 0 [less than or equal] r [less than or equal] 1 for expansions and r [greater than or equal] 1 for compressions.…

Two compounds, K[subscript 2][Cu(C[subscript 2]O[subscript 4])[subscript 2]] times 4H[subscript 2]O, 1, and K[subscript 2][Cu(C[subscript 2]O[subscript 4])[subscript 2]] times 2H[subscript 2]O, 2, were synthesized under controlled conditions. By controlling the concentration of the reaction solutions, it is possible to isolate a kinetic product 1…

A simple experiment about thermal effects in chemical reactors is described, which can be used to illustrate chemical reactor models, the determination and validation of their parameters, and some simple principles of heat transfer and sensor dynamics. It is based in the exothermic reaction between aqueous solutions of sodium thiosulfate and…

Storytelling is not just something experienced at bedtime, in the movies, or with friends. Rather, it is a way that knowledge has been transferred for generations. Stories allow the listener to gain understanding in a natural way. A good story can capture the imagination of students, making them eager to learn more. This article describes the use…

Chemical kinetics is an extremely important concept for introductory chemistry courses. The literature suggests that instruction in chemical kinetics is often teacher-dominated at both the secondary school and tertiary levels, and this is the case in Thailand--the educational context for this inquiry. The work reported here seeks to shift students…

Physics teachers often like to discuss physics concepts with their students on the basis of simple demonstration experiments. In this article, we discuss an experiment for which one only needs a few coins of the same denomination and a wooden stick: the coins are laid alongside the stick on a horizontal surface, the stick is rotated about one of…

A well-known classroom demonstration involves the rolling of hollow and solid objects down an incline. The fact that the objects roll at different rates can be used as a starting point in introducing students to rotational dynamics and rotational kinetic energy. In this paper we describe a simple quantitative version of the demonstration that is…

A two-week laboratory experiment for students in advanced inorganic chemistry is described. Students prepare and characterize a cobalt(III) complex coordinated by a thioether ligand during the first week of the experiment and then study the kinetics of Co-S bond cleavage in basic solution during the second week. The synthetic portion of the…

The process of quantitative imaging, which is very commonly used in laboratory, is shown to be very useful for studying the fast kinetics and fluorescence quenching of many experiments. The imaging technique is extremely cheap and hence can be used in many absorption and luminescence experiments.

The Celsius and Kelvin temperature scales, we tell our students, are related. We explain that a change in temperature of 1 degree C corresponds to a change of 1 Kelvin and that atoms and molecules have zero kinetic energy at zero Kelvin, -273 degrees C. In this paper, we will show how students can derive the relationship between the Celsius and…