Entropy and the second law of thermodynamics have long been identified as difficult concepts to teach in the physical chemistry curriculum. Their highly abstract nature, mathematical complexity and emergent nature underscore the necessity to better link classical thermodynamics and statistical thermodynamics. The objectives of this systematic…

The dissolution of cobalt­(II) chloride in an appropriate binary alcohol solvent yields an equilibrium mixture, consisting of the differently colored octahedral (pink in color) and tetrahedral (blue in color) cobalt­(II) coordination complexes, which can exhibit a brilliant and reversible pink-to-blue color transition over a ~10 °C window - i.e.,…

A laboratory experiment in which [superscript 1]H NMR and UV-vis spectroscopies are applied to probe the temperature dependence of a monomer-dimer equilibrium involving a cyclopentadienone derivative is described and discussed. Details of the data analysis for extraction of equilibrium constants from the raw experimental data from both techniques…

Energy conversion devices such as fuel cells, metal-air batteries, and electrolyzers have been envisaged as possible solutions for cutting down the continuous accumulation of greenhouse gases resulting from the combustion of fossil fuel. The bottleneck reaction for these devices is the oxygen reduction reaction (ORR) occurring at the cathode. The…

Anaerobic respiration reactions are of fundamental importance to global biogeochemical cycling of elements. Yet, the idea that cellular respiration can occur not only in the absence of oxygen but also involve the oxidation of inorganic substrates (e.g., AsO[subscript 3 superscript 3-], Fe[superscript 2+], H[subscript 2], H[subscript 2]S,…

We describe the components and implementation of an activity for multivariable calculus featuring applications to the field of chemistry. This activity focuses on the isobaric thermal expansion coefficient found using partial differentiation of the volume of an ideal gas with respect to temperature as pressure is held constant. Broader goals of…

An activity is described that uses simple materials and an easy-to-perform protocol to estimate the Curie temperature of nickel, which is the temperature at which nickel loses its ferromagnetism. To do so, an object made of nickel metal is heated with a lighter until it loses its ferromagnetism. The metal is allowed to drop into a beaker that…

The COVID-19 pandemic and its related restrictions forced the reorganization of learning methodology and gave a central role to remote learning. Laboratory experiments are the most affected activity, and several alternatives were described. This work proposes to create calculation tools by simply programming in Visual Basic of Excel to emulate the…

We describe an experiment in which students use research-grade instrumentation to collect gas adsorption data in triplicate in a single 3 h laboratory period. The experiment reinforces the thermodynamic concepts taught in upper level physical chemistry courses and hands-on experience with instrumentation used in research laboratories. The speed of…

The inexorable rise in atmospheric carbon dioxide impacts not only global warming but also the acidity of the ocean. Increasing ocean acidity causes a decline in carbonate (as it is protonated), which in turn will negatively impact the ability of calcifying marine organisms to build their calcium carbonate shells. A simple set of equilibrium…

In this laboratory experiment, students modify a series of surfaces and explore the effects of varying surface chemistry and texture on wettability by different probe liquids. Students begin by building a simple contact angle goniometer utilizing their mobile phone cameras. Next, they contrast the wettability of planar glass substrates…

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…

As simple and ubiquitous redox-active organic molecules, quinones participate in diverse electron transfer processes in chemistry and biological systems for energy transformation and signal transduction. We introduce here a practical exercise to study the redox potentials of benzoquinone and its two derivatives by combining the electrochemistry…

This study adds to the growing body of research on laboratory work. The study involves four pairs of students in a university introductory calorimetry lab of which two pairs, the IR-pairs (infrared camerapairs), were given access to infrared cameras to use however they liked during their course lab work. Two other pairs, the T-pairs…