A novel demonstration device for realizing the intuitive visual observation of the system's internal energy change is proposed. The device is safe, simple, and efficient, combining an infrared camera with a water bottle sprayer. With this setup, the changes of thermal images for air and helium during the compression and expansion processes were…

Under most conditions, a liquid mixture does not have long-range structural order and may be considered to be a homogeneous collection of molecules in random motion. However, if a single-phase critical mixture of a partially miscible liquid--liquid system is subjected to a small temperature jump into the two-phase region, then structural coherence…

In the vicinity of a critical point, the impact of a substance's chemical identity is superseded by universal critical behavior for a number of physical properties, such as visible light scattering. In this classroom demonstration, students observe a single-phase critical mixture of partially miscible isobutyric acid + water (IAW) as the…

Potassium tris(oxalato)ferrate(III) trihydrate is a commonly prepared coordination compound in general or upper-level chemistry laboratories and can be recycled to grow large single crystals that instructors may display when introducing the experiment to classes. Showing the crystal's shape can also be used to briefly introduce students to X-ray…

The liquid nitrogen cloud demonstration is an effective, dramatic, large-scale demonstration to illustrate gas laws and cloud/fog (aerosol) formations for classes and large-scale outreach events. When performed at full scale, it is common to produce a cloud 20-30 feet in height. Its effect can be further enhanced by adding brightly colored…

Water pollution has been one of the major issues of the present time. It is essential to educate students regarding this issue and its possible solutions. In this article, a demonstration of a typical adsorption-based water cleaning process is presented. The removal of methylene blue (MB) and detergent from an aqueous solution is demonstrated…

Photoacoustic imaging is a state-of-the-art technique that combines light excitation with ultrasound generation "via" the photoacoustic effect. Since sound waves at clinically relevant frequencies undergo minimal perturbation as they pass through the body, photoacoustic imaging is ideal for deep-tissue imaging applications "in…

This article describes a simple and inexpensive "shock and awe" classroom demonstration for understanding the importance of carbon dioxide (CO[subscript 2]) in acid-base regulation. Before class, a solution was prepared by adding sodium bicarbonate and universal indicator solution to a sample of distilled water contained in a standard…

In this article we describe a demonstration for most of the elements from the periodic table which together constitute the show "An Elemental Spectacle: A Guided Tour of the Darker Reaches of the Periodic Table."

Quantitative demonstration of chemical kinetics often requires sophisticated equipment and materials. By using inexpensive and commonly available chemicals, we propose here two clock reactions, oxygen-safranin-benzoin clock and cysteine-iodine-hydrogen peroxide clock. Students simply measure and add stock solutions to start clock reactions. Sudden…

Evidence-based reasoning and critical thinking are two crucial scientific abilities of students, sharing a close relationship with each other critical thinking is not just randomly refuting but a logical-reasoning thinking based on solid evidence. However, in real teaching circumstances of experiment classes, students easily directly accept the…

This work reports the first use of rubber latex waste as the hydrophobic reagent for a low-cost, simple, and rapid fabrication of a paper towel-based experimental device (PTED) with a circular design of 5 mm to demonstrate the factors affecting chemical equilibrium; this serves as a user-friendly means for a laboratory experiment. The illustration…

Augmented reality (AR) is a means of superimposing artificial 3D objects over the real world via a mobile device. An AR standard file format has been recently implemented on mobile devices that current students commonly own. Here we describe three relatively nontechnical methods to produce 3D AR objects for chemistry courses and demonstrate their…

The polarized optical microscope (POM) is an invaluable tool for characterizing materials such as liquid crystals and other optically anisotropic materials. Despite its frequent use in research settings, students are rarely introduced to its fundamental operation and importance. Curricula are starting to appear for applications of the POM in…

The authors describe the construction and use of tactile models for demonstrating intermolecular forces. These models are composed of inexpensive materials and can be used in college chemistry classrooms of varying levels including general and organic chemistry. The models were designed to be paired with an accompanying activity to encourage…