The design and operation of the vapor-absorption refrigerator (VAR) are described using the principles and tools typically covered in upper-division undergraduate physical chemistry courses. The objective is to enable students to understand in detail how this device works and how it compares with more typical vapor-compression refrigerators.…

Keto-enol tautomerism is a fundamental concept that examines the migration of a proton between two constitutional isomers, the keto and enol tautomer. Many experiments have been proposed to understand the concept behind Meyer's Rule, which states that the keto tautomer is favored as the solvent polarity increases. However, all the experiments have…

Molecules and Computer: Chemistry Calculations in Class (MC[superscript 4]) is a computational laboratory intended for final-year high school or undergraduate students. The topic is the antioxidant potential of anthocyanidins, which is chemically related to their radical scavenging action via the mechanism of hydrogen atom transfer (HAT). This…

Recently, scholars have suggested a co-design collaboration with instructors and students to effectively implement formative assessment (FA) practices because it ensures a high-quality design that considers users' needs, values, and goals in a specific learning context. This study examines the effect of co-designed FA practices, in which…

We present an empirical analysis of students' use of partial derivatives in the context of problem solving in upper-division thermodynamics. Task-based individual interviews were conducted with eight middle-division physics students. The interviews involved finding a partial derivative from information presented in a table and a contour plot.…

Physics and chemistry students learn several methods to determine the density of materials. While measuring the mass of materials is usually simple, volume measurements are more complex. For simple shapes the volume may be determined by measuring its geometry; for more complex shapes students often use Archimedes' principle. However, neither of…

This paper reports the development and application of a low-cost multifunctional webcam spectrophotometer for the conduct of molecular absorption and fluorometric measurements. The equipment, which costs approximately US$20 to be fabricated, consists of a webcam, a diffraction grating, and a slit, all positioned inside an MDF box. Spectral…

Students have several misconceptions about thermodynamics. However, an understanding of basic concepts in this branch of physics remains fundamental to explain thermal phenomena. The purpose of this activity was to extend students' conceptual understanding of heat, temperature, energy, and thermal insulators and conductors. Two groups of students…

The contemporary Human activity utilizes huge volumes of digital data to solve efficiently multiple socio-economic, scientific and technical problems. Now the big data analysis is mainly oriented to the socioeconomic sphere with a goal to lift the profit. The science and technology to penetrate deeper in the nature of objects and systems under…

The alternative conceptions that students hold put a brake on subsequent meaningful learning, and therefore, the identification of these wrong ideas is crucial for effective teaching and academic success. Undergraduate STEM students often perceive Chemical Thermodynamics as a difficult subject, in which entropy has been pointed out as a threshold…

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…

Seeking to foster the learning process and encourage the active participation of undergraduate students, this work proposes a new methodology that involves integrating smartphones into the learning process under a simple and accessible approach to learning in Chemistry and Physics laboratories aiming at facilitating the learning of some chemical…

This paper describes an upper-division undergraduate exercise involving the synthesis and iodometric and infrared spectroscopic analysis of the peroxide double salt [Zn(NH[subscript 3])[subscript 4]][Mo(O[subscript 2])[subscript 4]]. Here, iodometric methods are employed to determine the peroxide content of the compound, a procedure widely used…

When we teach thermodynamics, a vacuum container used to keep food isolated from air is a cheap and interesting teaching device. There are some experiments already described in the literature and we can also find videos of demonstrations on YouTube. At the same time, there is increasing interest in how to utilize smartphones in physics…

Iodonium zwitterions are hypervalent iodine compounds in which the iodine center binds to two substituents and carries a positive formal charge which is compensated by a negative charge within the same molecule. Under thermodynamic conditions, iodonium zwitterion sallow concerted nucleophilic aromatic substitutions to be performed, followed by…