Despite extensive conceptualization of ions as hard spheres in most textbooks, solid-state structures are more accurately modeled as overlapping soft spheres that better reflect the size of the ions. The corresponding soft-sphere ionic radii of alkali and halide ions can be empirically established from the partial molar volume of the ions in…

The analogy among momentum, heat and mass transport phenomena is an important concept in chemical engineering education. This paper presents the analogy between heat exchanger and packed column calculations. The effectiveness-NTU method used to calculate outlet temperatures of hot and cold streams in an exchanger is introduced in a packed column…

Low-dimensional materials especially graphene-based are of high interest to a broad community. One of the most fundamental aspects in the biomedical field is material characterization, which helps understand their property and tune for application. Though the existing teaching curricula are well standardized to include basic principles and…

The acoustic resonance in four glass Helmholtz resonators with diameters of 70, 52, 40, and 32 mm was detected in the frequency range of 360 to 1700 Hz using the simple experimental setup presented in this paper. The measured amplitudes of acoustic pressure required correction since the sound pressure amplitude of the loudspeaker used was not…

Colorful transitions of various acid-base indicators have been used to illustrate the concept of chemical equilibria, especially in spectrophotometric determination of the equilibrium constants or pKa values. To accommodate an online laboratory environment necessitated by the COVID-19 pandemic, this work employs color analyses from digital images…

Virtual laboratory simulations can contribute to the educational objectives related to practical classes, especially in situations of online or hybrid teaching. We present a proposal for laboratory activity involving the quantification of proteins with the biuret reaction and measurement by visible light spectrometry. The student will be able to…

An important objective of any analytical chemistry course is for students to generate and interpret data from the analysis of complex, real-world samples in order to assess the effectiveness of the analysis method, including the calibration. In this laboratory exercise, students directly compare calibration methods (external standards and standard…

These days, smartphones are popular commodities among students in high school and college. Students carry their devices all the time, so why not use such a popular electronic device to measure physical quantities such as "g" in physics labs? In this work, we report a "multiple tasking" method, a measurement technique that we…

This study is the result of a quantitative analysis of the previous paper reporting on four cases in which an LED is turned on by charge transfer occurring during the electrostatic induction process in a conductor connected to the LED. We were able to measure the charge transfer by using charge sensors and analyze experimental results by applying…

Understanding measurement uncertainty is crucial in experimental physics, as it enables accurate and reliable measurements, facilitates comparison between measurements, and aids in designing experiments. Consequently, measurement uncertainty has emerged as a critical learning goal for many introductory physics labs. Here, we explore the impact of…

Error analysis consumes much of the focus in introductory physics labs. Catastrophic cancellation is a spike in error that occurs when subtracting two measurements of roughly equal magnitude. Often termed "loss of significance" or "subtractive cancellation," this effect can easily relegate experimental results to utter…

Organic electrosynthesis is an increasingly popular tool for driving and probing redox reactions. Recent advances in this field often employ an electrocatalyst to enhance the selectivity and efficiency of electrochemical reactions. A laboratory experiment was developed to introduce students to relevant mechanistic techniques in electrochemistry…

In electrochemistry, the concept of a reference electrode is fundamental. Introductory courses might mention the standard hydrogen electrode (SHE), its working principle, and its theoretical design; however, chances are that students will never have the opportunity to work with one. A hydrogen electrode should be a device readily available at the…

The Arduino board and its communication with several sensors are becoming more and more popular in the physical science community. They offer inspiring possibilities for learning different physical concepts. In this article, we focused on creating a very practical educational system for experimenting with diffraction of laser light and graphically…

In this work, we have developed an alternative device composed by an Arduino board and an INA219 sensor to experimentally obtain the mathematical formulas describing the charge and discharge of the capacitor for educational proposes. We have obtained excellent agreement between theoretical prediction and experimental measurements. The INA219 DC…