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…

Photochemical reactions are the reactions that are induced by light. Many of these reactions are found in natural processes, including photosynthesis and the formation and decomposition of ozone in the atmosphere. Classroom demonstrations are effective in enhancing students' learning and retention. Herein, we have developed a simple demonstration…

The addition of research-focused experiences to undergraduate chemistry laboratory courses has been shown to bolster student learning, enhance student retention in STEM, and improve student self-identity as scientists. In the area of synthetic organic chemistry, the preparation of libraries of compounds with novel optical and electronic properties…

When structure-property relationships are discussed in inorganic chemistry and materials science, the common perception is that materials with the same composition and atomic arrangement have the same properties. In this laboratory experiment, we show that "processing"--the exact conditions under which materials are made--can in fact…

Conventional mobile phone colorimetry usually utilizes the RGB color mode to measure concentration of solutions, but the paper entitled "Determining the Amount of Copper(II) Ions in a Solution Using a Smartphone" proposes the use of hue ("H") to measure the concentration. It is pointed out that the "H" value increases…

Gravity bends light. One can argue this by reasoning that a beam of light should travel in a curved path when viewed from within an accelerating frame of reference, and then invoking Einstein's principle of equivalence, which asserts that the effects observed in an accelerating frame of reference are indistinguishable from the effects observed in…

What happens when a perfectly elastic ball collides with a completely inelastic ball? It is shown that the outcome depends on the stiffness of each ball. A standard textbook problem in mechanics is to calculate the outcome of a head-on collision between two balls using conservation of momentum and kinetic energy. It is easily shown that the…

We demonstrated that an optimally designed pinhole camera can be used as an astronomical tool to observe the libration and apparent diameter change of the Moon at night. The libration and apparent diameter change of the Moon were observed using a handmade pinhole camera with a diameter of 0.65 mm and a focal length of 400 mm. It was found that the…

In this guided inquiry experiment, students extract catecholase enzyme from apples to catalyze the oxidation of catechol. They follow the reaction using the UV--vis absorbance of the "p"-benzophenone produced to determine the Michaelis-Menten kinetic parameters. Students make selected experimental choices within a structured framework…

This article deals with an exploration of a double superior mirage obtained in laboratory conditions and its contribution to the deep understanding of light events in specialized schools. It was revealed that an explanation of the formation process of a double superior mirage plays a key role in the adoption of knowledge on reflection and…

Raman spectroscopy is an important vibrational spectroscopy tool to characterize chemical compounds. As only a few photons undergo Raman scattering, enhancement of signal is a vital requirement. In this laboratory experiment, some practical aspects of Raman spectroscopy and how a simple enhancement procedure can be used to detect a Raman signal…

The spectrophotometric determination of the percent composition of an aspirin tablet is a common first-year, general chemistry undergraduate laboratory procedure. The experiment requires that a known amount of pure acetylsalicylic acid be quantitatively converted into the soluble disodium salicylic acid that is further reacted with excess…

The objective of this study was to examine the effectiveness of blended physics laboratory experimentation on pre-service physics teachers' (PSPTs') understanding of the nature of science (NOS) during an electricity and magnetism laboratory course. The study used a non-equivalent comparison group using a pre-test-post-test quasi-experimental…

The chemistry of metal-organic frameworks (MOFs) has the potential to introduce high school and undergraduate students to the fundamental chemical principles of structure and bonding, enhance the development of skills in synthesis and crystal growth, and promote hands-on experience with gas capture and host-guest chemistry of emerging materials…

In this laboratory experiment, the synthesis and characterization of H[subscript 5]PV[subscript 2]Mo[subscript 10]O[subscript 40]@Cu[subscript 3](BTC)[subscript 2] (denoted as NENU[subscript -9], H[subscript 3]BTC = 1,3,5-benzenetricarboxylic acid) and its application in fuel desulfurization were performed. This experiment is designed for advanced…