The preparation of ethyl acetoacetate is a distinctive, century-old classic organic chemistry laboratory project. Ethyl acetate and sodium metal (sodium ethoxide) are reacted by Claisen ester condensation to produce the sodium salt of ethyl acetoacetate and then obtain the refined product by acidification as well as washing, drying, and…

If a ball rolls in a circular path on a horizontal surface at constant speed then its horizontal rotation axis changes direction with time. A simple experiment is presented showing that the torque applied to the ball is equal to the rate of change of its angular momentum, even though the magnitudes of its angular velocity and angular momentum…

We present a simple undergraduate level experiment dealing with the preparation and characterization of a colloidal Langmuir-Blodgett (LB) film. The experiment is designed to invoke an interdisciplinary understanding of colloid chemistry and surface science. It will allow the students to develop the concepts of wettability, hydrophobicity, and…

Measurements and calculations are presented showing how the trajectory of an object sliding across an inclined plane varies with the launch and incline angles. The trajectory depends on the magnitude and direction of the sliding friction force. The experiment is easy to set up, can be analysed using a video camera, and would be suitable for a…

Four General Chemistry instructors investigated the use of ChatGPT-4 to improve their lessons plans for the historical experiments of Thomson, Millikan, and Rutherford. The instructors varied in their prior knowledge for these experiments and their initial lessons addressed somewhat different learning objectives. This led to different…

Applying the idea of green chemistry, we extended an esterification teaching experiment with isoamyl alcohol and acetic acid and reused isoamyl acetate in the transesterification reaction with KOH as the catalyst. As a result, isoamyl alcohol was produced and could be reused for the teaching experiment. The simplified experimental method achieved…

The substitution of carbonyl compounds with liquid bromine as a brominating agent is the most commonly employed synthesis method for a-bromoacetophenone and its derivatives. However, liquid bromine possesses certain drawbacks, such as volatilization, high toxicity, strong corrosion, and poor reaction selectivity, which limit its application and…

The article describes a methodology for studying Fresnel diffraction with the active involvement of students in discussing the results of a demonstration experiment. To create a clearly visible model of Fresnel zones, a centimeter radio wave range was chosen, in which the first zone is about 10 cm in size. This makes visible the created…

The majority of chemical experiments conducted during educational programs are carried out in laboratories because they require instructors with special skills, in addition to large, expensive instruments. Recently, there has been an increasing demand for chemical experiments that can be carried out anywhere. Herein, we propose a novel type of…

Calculating analytical uncertainties as a part of method validation is a relevant aspect of field and laboratory practices in instrumental analytical chemistry subjects, which usually require complex algorithms. This work describes the development and didactic use of an automatic and straightforward informatics tool, implemented in an Excel macro,…

In science classrooms, students usually see and work with data that's intended to tell them right away about the natural world. Students then often treat the data we provide to them as factual, rather than as a source of evidence (Duschl 2008; Sandoval and Millwood 2005; Berland and Reiser 2009; McNeill and Berland 2017; Hancock, Kaput, and…

We describe here a low-cost experiment for introductory physics students where they compare the physical properties of aluminum and steel by means of cantilever oscillations. This, in turn, allows the students to improve their physical intuition about these materials. Further, the students can apply their physics and mathematics knowledge and…

In this paper, a very simple and low-cost setup design is described for the Seebeck coefficient measurement of the disc and rod-shaped specimens. The setup has been tested for its reliable working by measuring the Seebeck coefficients of standard samples; measured values match with the literature. The setup can be built with commonly available raw…

As intriguing optical phenomena that occur in nature, mirages are widely known and often mentioned in physics classes when introducing the basics of optics. In the atmosphere, a mirage occurs under the condition of vertical variations in air density, which are usually caused by a temperature gradient. The light rays are continuously refracted and…

To present the difference in oxidizing strength in concentrated and dilute nitric acid reacting with copper, a simple, facile demonstration of these reactions is designed using a waste plastic bottle, plastic droppers, and syringes, which are costless and easily assembled. This new version can be used to demonstrate the difference in oxidizing…