Experiments serve different purposes in chemistry education ranging from illustrating a certain subject matter to providing data for school-based research projects. When students use these experiments to collect data and draw conclusions, it is important that these experiments are valid. In this study, a new experiment for the determination of the…

The reflection and refraction of light are more familiar to students than the reflection and refraction of sound. Reflection and refraction that occur during the transmission of sound waves are common phenomena in everyday life but are often difficult to understand during actual learning. In this study, we developed a sound reflection and…

This work describes the design and testing of a low-cost light-emitting diode (LED)-based nephelometer for turbidity analysis. It also describes the use of this nephelometer for context-based learning (CBL) experiments designed for teaching laboratories. The LED nephelometer is simple, low-cost, and robust, providing similar results as a…

Drop Tower Physics (DTP) is composed of a set of experiments using standard physics lecture demonstration equipment, such as a pendulum, mass spring oscillator, and so forth, while videotaping them as they fall freely in the Dryden Drop Tower in Portland, OR. An article published in "The Physics Teacher" illustrated the behavior of a…

Photogates play an important part of many of today's physics laboratory experiments. They signal when an infrared (IR) beam is interrupted, thus supplying the experimenter with important timing information. Currently photogates use an infrared photodiode (IR transmitter) and a phototransistor (IR receiver). User-built photogates have a weakness…

Although it originates from the ancient Greeks, optics still arouses a lot of scientific interest, mainly due to the technological innovation associated with it. One of its most interesting applications is related to optical metrology and the characterization of materials through optical techniques. While some of these processes can be explained…

A cost-effective method has been developed with utmost efficiency for the determination of density of a liquid. The experimental setup for this purpose is a Polyvinyl chloride (PVC) cylinder fitted with an overflow spout, a volume measuring cylinder, a wooden block along with a hook and a known mass taken from scientific weight box. For this…

This paper outlines a comprehensive teaching laboratory course program that centers on titration analysis, a timeless and essential technique in analytical chemistry spanning various disciplines, such as environmental science, medicine, and industry. In these fields, titration analysis is paramount for determining the concentrations of substances…

Nowadays, electronic devices (especially smartphones) are developed to use as an alternative tool for recording experimental data in physics experiments. This is because of the embedded sensors in a smartphone such as the accelerometer, gyroscope, magnetometer, camera, microphone, and speaker. These sensors were used in physics experiments, such…

Although ripple tanks have been used in the past to perform wave simulations for electromagnetic and acoustic phenomena, especially before the advent of computers, they are still often used to demonstrate wave propagation in high school and college physics classrooms. Usually ripple tanks have a rectangular shape. The wave propagating through the…

In this article we present a simple experimental set-up to determine the band gap of germanium and silicon using the "ExpEYES-17" kit. The experiment is based on the temperature dependence of the reverse current through germanium and silicon diodes at different temperatures. The experimental values are found to agree well with accepted…

Kundt's tube is a popular experiment commonly used in schools, in which standing sound waves are made visible inside a glass tube. A fine powder is stirred up in areas of high sound particle velocities, so that one can measure the wavelength of the sound waves by examining the patterns created. In this way, the 'invisible' can be made visible.…

The use of radioactive isotopes in radioactive decay studies can be a problem due to the manipulation of radioisotopes, expensive equipment, and the difficulty of finding samples with a reasonable half-life (between 1 and 10 min). In this paper, we present a mock-up of a Geiger-Mu¨ller counter plus three fictitious radioisotopes. They form an…

We present a thermodynamics experiment suitable for first year undergraduate students employing Stirling Engines to create a demonstration of energy transformation and to measure the mechanical efficiency of such engines. Using an inexpensive transparent chambered Stirling Engine, students can connect concepts such as the theoretical…

Technically simple and extremely cheap setups for colorimetric and fluorimetric analyses using a smartphone camera are presented. Laboratory activities on digital colorimetric and fluorimetric analyses for students of secondary and higher educational institutions are proposed, namely, photocolorimetric determination of acetylsalicylic acid in…