This study expanded the "cell agglutination reaction" experiment in undergraduate cell biology teaching by integrating a sugar inhibition component. Lectins bind to specific sugars. In the traditional cell agglutination reaction, lectin is used to cause cells to aggregate via binding to sugars present on the cell surface. Here, various…

The UV--vis absorption of cyanine dyes is a common experiment in many physical chemistry teaching laboratories. As part of the analysis, students are often asked to hypothesize why the predicted absorption differs from the measured values and why dyes which are predicted to have the same absorption have measured values which differ from each…

In school chemistry, the oxyhydrogen or "Knallgas" reaction is used to provide evidence of hydrogen gas in the squeaky pop test. However, the test actually indicates the presence of an explosive gas mixture of hydrogen and oxygen (oxyhydrogen gas) rather than pure hydrogen. The sheer observations of an explosive reaction and the…

A simple, safe, and easy demonstration of the reaction of sodium peroxide with water is presented. The reaction is performed in a plastic bottle by adding water to sodium peroxide supported in a rubber "thimble"; oxygen is detected by the reignition of a glowing splint, while the generation of sodium hydroxide is indicated by…

To effectively demonstrate the transformation of ethanol into acetaldehyde, a simple, low-cost, and eco-friendly reaction demonstration was designed, in which a Y-shaped tube served as the reactor, condenser, and detector with the help of specific reagents. The ethanol was added via a transparent elephant nose spray bottle fixed to the top of the…

The self-association of caffeine in solution, driven by the hydrophobic effect, is a simple example of molecular aggregation. It obeys an isodesmic association model in which each successive binding occurs with the same equilibrium constant. Here, we describe an activity for chemistry students that explores this phenomenon using nuclear magnetic…

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…

Colloidal stability is one of the most important criteria in the application strategy of colloidal nanoparticles in the continuous phase. The branches include ecology, involving coagulation as a purification method; medicine as nanocarriers; biology as blood coagulation, etc. A chemist versed in these concepts is a high-performing chemist in…

The area of application of electrospray ionization mass spectrometry (ESI-MS), usually coupled with liquid chromatography, seems to be much larger than those of any other ionization method. It gives rise to the demand for new teaching methods that would effectively help students to master the principles of working with and making full use of the…

Experiments that explore quantum principles while utilizing and reinforcing previous synthesis skills are excellent for engaging students and promoting the interconnected nature of chemistry. This experiment utilizes sophomore-level organic synthesis techniques to have students produce their own "meso" substituted porphyrins. The UV-vis…

The main objective of this four-year empirical research project has been to develop the experimental design skills of 12-16 year-old Hungarian pupils in Grades 7-10 of junior high school through guided inquiry, using six chemistry experiment worksheets each school year. Group 1 (control group) and Group 2 follow step-by-step instructions, but…

In the environment, communication among microorganisms is a key aspect of their lives. Through communication, single cells of a microbial population can coordinate their gene expression and, in consequence, their physiology. Quorum sensing systems (QS) are one of these mechanisms that allow this communication through the production and detection…

At-home chemistry experiments are increasingly important to enable high-quality online and hybrid instruction. These class modalities provide significant challenges and also dramatically expand the accessibility of education to those who work or care for family during traditional school hours or have significant commutes to campus. This work…

The importance of teaching the Luria-Delbrück experiment to biology students is increasingly recognized by educators, and improved pedagogical methods for teaching the classic experiment have been proposed and tested in the classroom. However, there are still obstacles that impede the proper teaching of the classic experiment. This note proposes…

Ion transport, involving the diffusion and migration of ions within the electrolyte, stands as a fundamental concept in electrochemistry and serves as the driving force for electrochemical reactions. Electric double layers are critical in the fields of electrochemical energy storage and chemical conversion, constituting a central focus of…