This paper describes our bench-scale student experiment with a continuous stirred tank reactor (CSTR). The conditions under which the CSTR approaches ideal mixing behavior are investigated using CaCl[subscript 2(aq)] as a tracer. The data are derived from transient solution conductivity measurements of the vessel effluent. Adjustable parameters…

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…

Owing to factors such as poor water solubility of luminol and the instability and easy decomposition of hydrogen peroxide (H[subscript 2]O[subscript 2]), the accuracy and sensitivity of the detection of H[subscript 2]O[subscript 2] through the luminol electrochemiluminescence (ECL) system are limited. Herein, we propose a water-soluble…

The Folch method is a commonly employed, simple biochemical procedure used to extract fat from food items and biological samples in biochemistry laboratories. The iodine number of fat reflects its degree of unsaturation. In the present study, the iodine number of fat extracted using the Folch method from cow milk, goat milk, chicken egg yolk and…

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…

Bacteria have developed a cell-to-cell communication system called quorum sensing (QS), allowing them to regulate group behavior and synchronize the expression of virulence factors, responsible for increasing their infection capacity and resistance to antimicrobials. Although the control of microbial infections through the inhibition of microbial…

Paal--Knorr reactions are a classical method for synthesizing pyrroles, using 1,4-dicarbonyl compound and amine as reactants. It has the characteristics of green chemistry, as only two molecules of water are lost. In this teaching and learning experiment, 2,5-hexanedione and 4-"tert"-butylaniline were used to synthesize…

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…