For single-slit diffraction and double-slit interference experiments, commercially made slits can be the most expensive parts, especially since the prices of laser pointers have become very low. One option is to use a razor blade to cut slits in either paint or electrical tape on microscope slides. However, this takes practice, and there is some…

The dehydration of 2- or 4-methylcyclohexanol to obtain isomers of methylcyclohexene is a classic organic chemistry experiment. Students perform a distillation, collecting samples to analyze the progress of the reaction. The reaction produces a major product that can be explained on the basis of the regiochemistry of the [pi] bond formation for…

A study with K-9 Greek students was conducted in order to evaluate how the declarative knowledge acquisition was affected by incorporating Arduino experiments in secondary Chemistry Education. A Digital Application (DA) that blends the use of the Arduino sensors' experiments with digital educational material, including Virtual Labs (VLs), was…

We describe an educational activity that can be done by using smartphones to collect data in physics experiments aimed to measure the oscillating period of a spring-mass system and the elastic constant of the helicoidal spring by the dynamic method. Results for the oscillating period and for the elastic constant of the spring agree very well with…

Supersonic free-fall jumps are excellent examples of kinematics in the context of drag. They have attracted a lot of media, public, and scientific interest. In 2012, Felix Baumgartner jumped from a height of approximately 38.969 km. During his flight he reached a top speed of 373 m/s, becoming the first human to travel faster than the speed of…

In this paper, we show a laboratory experience describing the possibility to build a sensor using a coil to measure small thicknesses of materials with the possibility of measuring temperature simultaneously, with the same built sensor. Its operation is based on the following facts: An electric current (a.c), flows through a coil and a magnetic…

We report on a simple, rapid, and room-temperature undergraduate-level experiment for gold nanoparticle synthesis, analysis, and utilization as a catalyst for the sodium-borohydride-assisted reduction of methylene blue and Congo red dyes. Typical procedures toward gold nanoparticle formation require an elaborate, lengthy synthesis (some requiring…

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…

All-solid-state polymer electrolytes (SPEs) have been regarded as an advisible alternative for simultaneously overcoming the safety issues and high energy density demands presented in traditional lithium batteries, and they represent the development orientation of energy storage devices. This course describes the preparation of a cross-linked and…

Secondary metabolite compounds contained in each plant genus have certain characteristics, which is true also of the flavonoid in the genus "Artocarpus." In the experiment described here, third-year undergraduate students performed the isolation and characterization of cycloartocarpin from the roots of "Artocarpus altilis"…

According to the definition, surface tension could be affected not only by intermolecular interaction but also by molecular area. However, in chemistry textbooks, surface tension is mainly explained only in terms of intermolecular interaction. Although the existing surface tension concept in the textbooks can lead to a variety of counterexamples,…

A classic undergraduate introductory experiment is to measure the diffraction and interference pattern from single and double slits to determine slit width and separation. Studies show that Course-based Undergraduate Research Experiences (CUREs) can make science more inclusive when offered at the undergraduate level. Additionally, CUREs help…

A laboratory exercise for the synthesis of a sulfonated styrene-"co"-maleic anhydride polymer and its application as a stain blocker on nylon-6,10, is described. The effectiveness of the sulfonated polymer to prevent the conjugate base of an acid dye from staining the polyamide is demonstrated. This experiment is designed for…

To study the absorption of ultrasound in plexiglas we propose to use gadgets that are available to each student: an ultrasound humidifier, a liquid crystal display of a pad, a polaroid analyzer, a digital camera, a multimeter with thermocouple, and a stopwatch. These devices allow us to visualize a region in plexiglas where ultrasound is absorbed…

Newton's law of cooling describes an object whose temperature decreases exponentially with time. Because of its many applications, it is a frequent topic of introductory physics labs. In this article, I describe an experiment designed for the freshman year algebra-based physics course that applies this law to answering the question, "Why…