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…

A fast, operationally simple, and reproducible synthetic protocol for anthraquinone dyes (AQDs), suitable for upper-division undergraduate industrial and organic chemistry laboratory courses, has been developed. This experiment is composed of three stages; the first step deals with the synthesis of AQDs, followed by a purification step, and…

An introductory normal phase column chromatography experiment is described and evaluated for second year undergraduate chemistry laboratory class. The experiment involves a nucleophilic substitution yielding a crude mixture of reactant and one product, both of which are brightly colored and contrasting, creating a clearly visual separation when…

A chemistry laboratory experiment is described to introduce undergraduate college students to membrane separation technology. This experiment combines a simple nanowire membrane fabrication and visually indicated molecule separation. The membrane is produced via coprecipitation synthesis followed by a filtration assembly process, which can be…

There has been dramatic growth in interest and research regarding organic photochromism in recent decades. Despite this, the topic is seldom addressed in the undergraduate chemistry curriculum. Herein, we present a straightforward and robust experiment for the second semester organic chemistry laboratory curriculum which combines multistep…

Quinacridone red and violet are visually different colors, an observation confirmed by their visible reflectance spectra and CIE L*a*b* coordinates. However, their IR spectra are extremely similar. Though chemically identical, the two quinacridones are polymorphs. In this experiment, designed for and tested by nonscience majors, the pigments are…

Ever since Newton's groundbreaking work on the composed nature of light, additive colour mixing (and its laws) are subject to the interest of physicists as well as other sciences. In this paper, we present a setup for simple lab or home experiments on additive colour mixing and the laws of colour mixing. Students use the screen of a laptop or…

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…

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…

Introducing chemical equilibrium concepts in undergraduate general chemistry promotes improved understanding of chemical reactions. We have developed an engaging laboratory experiment exploring the equilibrium of cobalt complexation in alcohols using UV-vis spectroscopy and successfully implemented in a large general chemistry class of 378…

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…

The Leidenfrost nanochemistry synthesis of gold colloids was introduced in this "Journal" as an advanced method to synthesize gold nanoparticles during an undergraduate nanochemistry research project. When trying to repeat these experiments in the laboratory, we experienced difficulties in the synthesis of the gold nanoparticles since…

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…