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…

Removing the pollutants from various wastewater is crucial to the environment, ecology, and humans. However, the pollutants are generally removed by chemical decomposition, which not only consumes a lot of energy but also produces carbon emissions. Electrochemical flocculation is effective to extract pollutant molecules and heavy ions from…

Recently, smart sensing/actuation paper has attracted significant interest due to its potential usage as a sustainable component in future electronics, robotics, and intelligent sensing devices. In acknowledging the importance of this topic for the engagement of students at the university level in conjunction with Industrial Revolution 4.0, it is…

By hosting a college students' laboratory skills contest, we provide an interesting activity for students to cultivate good laboratory practices and thereby improve their laboratory skills. The substance of this contest is the detection of the hardness of water, which involves numerous laboratory skills such as solution preparation, weight by…

This laboratory experiment introduces students to an important reaction in biomass valorization and allows them to gain a practical understanding of green chemistry. Acid-catalyzed dehydration reactions of fructose to 5-hydroxymethylfurfural and thus humins were performed both with and without aqueous solvent, along with two different catalysts…

A laboratory experiment that involves the synthesis, characterization, and application exploration of a metal-organic framework (MOF) has been developed for first-year undergraduates in the Faculty of Engineering at National University of Singapore. The desired MOF material was prepared from commercially available reagents in a facile…

In this guided-inquiry lesson, students were tasked with determining the efficacy of an at-home drinking water filter at removing lead (Pb) from tap water using graphite furnace atomic absorption spectroscopy by determining the concentration of lead before and after filtration. The lesson was structured to allow students to choose and perform…

A newly developed laboratory learning program for high school chemistry courses is discussed, in which students discover the chemical mechanism governing exothermic phenomena during the reaction between a heating agent, namely, calcium oxide (CaO)--aluminum (Al) mixture, and water. Based on prior knowledge of simple heating agents such as CaO, the…

The concept of equilibrium vapor pressure plays a key role in the general chemistry curriculum; it is among the first and most easily demonstrated examples of equilibrium and frequently caps off the first semester of general chemistry where it illustrates the properties of liquids and intermolecular forces. We report here simple modifications of…

When the thermal expansion of water is discussed in school or university lessons, functional relationships are often inferred without considering measurement uncertainties. Moreover, in some learning materials, the goal of experimentation and the experimental setup do not match. This creates the wrong picture of scientific practice. In this…

Water exhibits a maximum in density at normal pressure at around 4° degree temperature. This paper demonstrates that during cooling, at around 4 °C, the temperature remains constant for a while because of heat exchange associated with convective currents inside the water. Superficial approach implies it as a new anomaly of water, but actually it…

Micellar catalysis has become an important aspect of the chemical industry's effort to "go green". However, this chemistry has yet to be fully explored in educational settings such as second-year organic chemistry laboratories. Reported herein is a discovery-based nucleophilic aromatic substitution experiment that introduces chemistry…

Adsorption of methylene blue and malachite green was carried out using "Luffa cylindrica" sponges as adsorbing material. We provide a very illustrative exercise about the use of common natural materials requiring little preparation to solve environmental tasks in a routine laboratory situation such as using dyes. In addition, the…

A new laboratory experiment investigating the ternary phase equilibrium of water-propan-2-ol-sodium chloride with one-, two-, and three-phase regions has been developed. Observations of the type and number of phases of a series of mixtures of the three components were made, and the results are then used in a systematic way to more finely choose…

In hydrostatics, pressure measurement with U-gauges and their relationship to density is a well-known experiment. Very little is studied or experimented with the dynamics of the movement of a liquid in a U-tube probably due to its theoretical complexity but, after all, it is a simple damped oscillating system. In this paper we present a relatively…