The study of buoyancy becomes very interesting when we measure the apparent weight of the body and the liquid vessel weight. In this paper, we propose an experimental apparatus that measures both the forces mentioned before as a function of the depth that a cylinder is sunk into the water. It is done using two load cells connected to an Arduino.…

Polychlorinated biphenyls (PCBs) are a family of synthetic chemicals consisting of carbon, hydrogen, and chlorine atoms. PCBs have been produced commercially since 1929 in hundreds of industrial applications. Their continued production in the United States was phased out in the late 1970s, and strict disposal guidelines were regulated as adverse…

The anomalous thermal expansion of water in the 0 °C-4 °C range is extremely important to life on Earth, but it is normally not presented experimentally in educational settings. This paper presents a simple experiment to explore the anomalous thermal expansion of water in the 0 °C-4 °C range and the heat exchange processes in natural bodies of…

An experiment to match five white solids with ascorbic acid, citric acid, potassium hydroxide, sodium chloride, and urea is reported here. This 4 h experiment is an integrated practice of two experimental techniques, calorimetry and titration. Students conduct an extensive literature search on the properties of the five compounds and plan the…

This paper describes an experiment with two touching rotating disks, whose movement is followed by video analysis. Within the disks' movements, there are intervals with sliding and intervals without sliding, that is, intervals with frictional forces between the touching surfaces and intervals without it. This system configuration allows for…

Photocatalytic degradation of methylene blue was implemented as a laboratory experiment by the undergraduate students majoring in chemical education using graphene (GR)/TiO[subscript 2] as a catalyst. These chemistry preservice teachers synthesized a GR/TiO[subscript 2] composite and used it to degrade wastewater containing methylene blue under…

As e-commerce increases, the demand for packaging materials and the potential for generating waste and negative environmental impacts also rise. Packing peanuts are a type of plastic packaging material that are used to protect goods during the shipping process. Petroleum-based plastics are common packaging materials due to their low cost, light…

Laboratory exercises for undergraduate biochemistry students are described in which changes in sugar content during fermentation of the trendy beverage kombucha are analyzed by three methods: thin layer chromatography, a 3,5-dinitrosalicylic acid assay, and a standard commercial blood glucose meter. Each of the three analyses can be completed in a…

A simple and economical system that allows one to obtain the characteristic "I-V" curve in solar cells is presented. It is a computer-controlled system suitable as an instrumentation project for students who are learning about photovoltaic systems. This system is based on the use of an "R-3R" ladder circuit as a variable…

Adsorption of methylene blue and malachite green was carried out using "Luffa cylindrica" sponges as adsorbing material. We provide a very illustrative exercise about the use of common natural materials requiring little preparation to solve environmental tasks in a routine laboratory situation such as using dyes. In addition, the…

To inspire upper-division undergraduate students to gain a deeper understanding of biorefinery, an experiment related to biofuels and lignin-based sunscreen products from corncob was performed in multiple offerings of a summer-semester class. Specifically, corncobs were pretreated with 1% H[subscript 2]SO[subscript 4] to obtain hemicellulose…

Disrupting a gene to determine its effect on an organism's phenotype is an indispensable tool in molecular biology. Such techniques are critical for understanding how a gene product contributes to the development and cellular identity of organisms. The explosion of genomic sequencing technologies combined with recent advances in genome-editing…

This practical is aimed at students who have been introduced to the tableting process, drug delivery systems, and dissolution. The student can design and manufacture a tablet investigating the effect of excipients and their role in tablet design and then generate a release profile of the tablet by using a dissolution apparatus, flow-through cell,…

In this article, the dynamics of a traditional toy, the yo-yo, are investigated theoretically and experimentally using smartphone sensors. In particular, using the gyroscope the angular velocity is measured. The experimental results are complemented thanks to a digital video analysis. The concordance between theoretical and experimental results is…

This paper demonstrates the use of smartphones in an experiment of light absorption and light scattering. The LED display and camera of the smartphone are used as the light source and as the detector, respectively. The color wheel is used to choose the color of the light source to be shone through the sample for analysis. The detector directly…