Lakes are artists' pigments made from colorants bound to an inert substrate, usually hydrated aluminum oxide. Before the late 19th century, lakes were made from natural pigments extracted from plants and insects, extracted either directly from the dyestuff or indirectly from waste materials generated in the manufacture of dyed textiles. The first…

This experiment demonstrates that copper(II) chloride dihydrate (CuCl[subscript 2]·2H[subscript 2]O) in different solvents (acetone, isopropyl alcohol, or water) displays divergent colors and visible-near IR spectra. Both the reactions of these solutions with 2 equiv of sodium hydroxide (NaOH) and the direct solid-state reaction of CuCl[subscript…

A new organic chemistry experiment aimed to separate the chlorophyll precursor in plant seeds by column chromatography is described. The primary pedagogical goal in developing this experiment is to establish a simple and interesting chromatographic separation to demonstrate basic concepts and the standard procedure for this important lab…

So-called "Color Wonder" markers contain colorless dyes that only display color when used to mark on special "Color Wonder" paper. These markers make use of leuco dyes that only develop color in the presence of acid. These markers provide science educators with a novel chemical system that can be implemented in inquiry-based…

Green fluorescent protein has long been a favorite protein for demonstrating protein purification in the biochemistry lab course. The protein's vivid green color helps demonstrate to students the concept(s) behind affinity or ion exchange chromatography. We designed a series of introduction to biochemistry labs utilizing a thermostable green…

A major challenge when designing new experiments for the general chemistry laboratory is introducing students to the necessary techniques while keeping the experiment engaging and accessible. This work presents a new multiweek activity designed to introduce students to advanced instrumentation in the form of high-performance liquid chromatography…

The identification of coloring substances is a relevant task in the field of conservation and restoration, but it can be challenging as in real samples the target analytes are inserted in a very complex matrix made of binders and additives. Understanding this concept is fundamental for upper-division undergraduate students interested in…

The "Golden Penny" demonstration is a popular experiment that involves treating copper coins with chemical reagents to form brass, an alloy of copper and zinc that has a golden color. Reported here is a very simple modification for forming golden color on copper coins that does not require the use of chemical reagents. Instead, golden…

In this paper, a simple method is described for visually demonstrating that the wavelength of light reduces when entering a medium of higher refractive index. When a violet laser (405 nm) is reflected off the surface of a Blu-ray disc (track spacing 320 nm) diffraction cannot occur since the wavelength is greater than the track spacing. However,…

Mobile phones are a widely used platform for educational apps, mobile health, and a variety of chemical tests. Here, we are working on a mobile phone-based physics lab (mPhysics) that uses a mobile phone's capabilities to run simple physics experiments and demonstrations. While a mobile phone can be used to analyze magnetic and optical properties…

Blue (B), yellow (Y), red (R), and green (G) color-changing dye was used in a general chemistry course for first-year undergraduate students with nonscience majors to highlight the redox reactions written as the gain and loss of hydrogen. The first experiment is a vibrant color variation using a synthetic dye of indigo carmine. The second…

There is an increasing need for fundamental electrochemistry concepts to be taught in the undergraduate curriculum, given the broad applicability of electrochemical technologies in addressing a wide range of global issues from critical energy shortages to real-time medical diagnostics. However, many electrochemical concepts are often taught in…

Thin-layer chromatography, which involves the movement of dyes along a silica-coated plate, is used to observe the progress of chemical reactions and to separate mixtures. We took advantage of this phenomenon to devise a method for generating patterns in the shape of numbers with dots (dot matrix). We prepared the azo dyes necessary for generating…

In the course of combining the Sustainable Development Goals (SDGs) with the science education curriculum, the relevance of the micro- and macroalgae in education is based on the biotechnological future-oriented significance and the ever-growing trend toward plant-based nutrition. So, the micro- and macroalgae are finding their way onto the food…

The laser pointer has been widely used to demonstrate some simple optics phenomena, like reflection, refraction, total reflection, and diffraction. However, the rays of laser light cannot be seen in the air because the scattered light is too weak. Many physics teachers use milk or smoke to visualize rays of laser light in physics labs, but it is…