This study reports an undergraduate laboratory experiment that explores the temperature-dependent kinetics of caffeine release during tea steeping by using quantitative [superscript 1]H NMR spectroscopy with a water suppression pulse sequence. Designed for introductory organic chemistry laboratory courses, the experiment emphasizes the real-world…

Concepts relating to enzymes and energy are central to understanding chemical and biological processes at the molecular level. Student learning of these crosscutting concepts can be challenging, so it is important to identify misconceptions and remediate them early, especially in introductory classes. Here we describe an activity in which…

Even though physical experiments are mandatory in science education, there has been an increasing demand for virtual experiments. This research aimed to investigate the impact of virtual experiments compared to physical experiments on students' conceptual understanding of chemical kinetics concepts. To achieve this, a two-phase explanatory…

This report describes a laboratory experiment for an undergraduate-level inorganic chemistry or biochemistry course involving the study of the kinetics of the catecholase activity of a synthetic nickel­(II)-oximate complex. A model substrate, 3,5-di-tert-butylcatechol(DBC), undergoes aerobic oxidation to 3,5-di-tert-butylbenzoquinone (DBQ) in the…

Millions of people do not have access to clean drinking water; thus, cost-efficient water treatment systems are vital. Chemists, environmentalists, technicians, and engineers will be the professionals making breakthroughs in this industry. This laboratory experiment aims to introduce undergraduate students to the removal of pollutants from water…

A laboratory experiment that exposes students to fundamental concepts in kinetics and statistical thermodynamics to study systems of great current interest in nanotechnology by employing a foundational technique in physical chemistry is described. A modified commercial flash photolysis spectrometer was used to study photoinduced isomerization…

A laboratory experiment is described in which students carry out immobilization of the enzyme invertase via entrapment in alginate (Ca-alginate) and, accordingly, estimate values for kinetic constants and mass transfer coefficients. Immobilization of enzymes, or confinement thereof to a defined space with retention of most catalytic activity, is…

The principles of chemical kinetics comprise one of the core topics that appear throughout chemistry. Standard kinetics lessons typically cover reaction rates and relative rates, rate laws, integrated rate laws, half-lives, collision theory, and the Arrhenius equation. They can also introduce a discussion of mechanisms as well, which may be the…

Enzyme kinetics is an essential topic in undergraduate Biochemistry courses. A laboratory work that covers the principal basic concepts of enzyme kinetics in steady state is presented. The alkaline phosphatase catalyzed reaction of phenyl-phosphate hydrolysis was studied as a model. The laboratory experience was designed to reinforce the concepts…

Thomas Graham discovered the law that bears his name while studying gas diffusion into air and other gases. He also found that the same relationship held with gas effusion, the movement of gases through a pinhole into a vacuum. Modern understanding of diffusion and effusion is based on kinetic-molecular theory, and it is generally accepted that…

Supersonic free-fall jumps are excellent examples of kinematics in the context of drag. They have attracted a lot of media, public, and scientific interest. In 2012, Felix Baumgartner jumped from a height of approximately 38.969 km. During his flight he reached a top speed of 373 m/s, becoming the first human to travel faster than the speed of…

In order to introduce students to the fascinating field of femtochemistry, we propose here a practical laboratory training course conceived for second-year master's students in chemistry. We describe the use of a broadband femtosecond transient absorption (pump-probe) experiment for monitoring a fast light-triggered chemical reaction in solution.…

Herein we present a modified iodine clock experiment which replaces starch with cellulose paper. This provides the reaction with a white solid surface in which color change can be clearly observed and reduces reagent amounts required to 540 µL per group. After data acquisition, students are required to calculate reaction orders and the reaction…

This work reports a rudimentary approach to teach and measure the kinetic friction coefficient using a smartphone that can effectively be employed for teaching purposes. More specifically, the kinetic friction coefficient, which is rather difficult to teach and measure, between various surfaces was determined by two different approaches using the…

We have developed a laboratory project in which students prepare liposomes, expose them to hyperosmotic and hypoosmotic solutions, and follow the resulting shrinking and swelling (respectively) with laser light scattering. Each light intensity transient can be fit to an exponential decline or rise, with the decay constant (k) and the amplitude…